nixos-render-docs: add examples support

the nixos manual contains enough examples to support them as a proper
toc entity with specialized rendering, and if in the future the nixpkgs
wants to use nixos-render-docs we will definitely have to support them.
this also allows us to restore some examples that were lost in previous
translation steps because there were too few to add renderer support
back then.

5 files changed, 22 insertions, 18 deletions

diff --git a/nixos/doc/manual/development/freeform-modules.section.md b/nixos/doc/manual/development/freeform-modules.section.md
index 514a06f97ee..4f344dd8046 100644
--- a/nixos/doc/manual/development/freeform-modules.section.md
+++ b/nixos/doc/manual/development/freeform-modules.section.md
@@ -13,7 +13,7 @@ checking for entire option trees, it is only recommended for use in
 submodules.
 
 ::: {#ex-freeform-module .example}
-**Example: Freeform submodule**
+### Freeform submodule
 
 The following shows a submodule assigning a freeform type that allows
 arbitrary attributes with `str` values below `settings`, but also
diff --git a/nixos/doc/manual/development/option-declarations.section.md b/nixos/doc/manual/development/option-declarations.section.md
index f6fed3e1683..3448b07722b 100644
--- a/nixos/doc/manual/development/option-declarations.section.md
+++ b/nixos/doc/manual/development/option-declarations.section.md
@@ -77,6 +77,7 @@ The option's description is "Whether to enable \<name\>.".
 For example:
 
 ::: {#ex-options-declarations-util-mkEnableOption-magic .example}
+### `mkEnableOption` usage
 ```nix
 lib.mkEnableOption (lib.mdDoc "magic")
 # is like
@@ -126,6 +127,7 @@ During the transition to CommonMark documentation `mkPackageOption` creates an o
 Examples:
 
 ::: {#ex-options-declarations-util-mkPackageOption-hello .example}
+### Simple `mkPackageOption` usage
 ```nix
 lib.mkPackageOptionMD pkgs "hello" { }
 # is like
@@ -139,6 +141,7 @@ lib.mkOption {
 :::
 
 ::: {#ex-options-declarations-util-mkPackageOption-ghc .example}
+### `mkPackageOption` with explicit default and example
 ```nix
 lib.mkPackageOptionMD pkgs "GHC" {
   default = [ "ghc" ];
@@ -156,6 +159,7 @@ lib.mkOption {
 :::
 
 ::: {#ex-options-declarations-util-mkPackageOption-extraDescription .example}
+### `mkPackageOption` with additional description text
 ```nix
 mkPackageOption pkgs [ "python39Packages" "pytorch" ] {
   extraDescription = "This is an example and doesn't actually do anything.";
@@ -217,7 +221,7 @@ changing the main service module file and the type system automatically
 enforces that there can only be a single display manager enabled.
 
 ::: {#ex-option-declaration-eot-service .example}
-**Example: Extensible type placeholder in the service module**
+### Extensible type placeholder in the service module
 ```nix
 services.xserver.displayManager.enable = mkOption {
   description = "Display manager to use";
@@ -227,7 +231,7 @@ services.xserver.displayManager.enable = mkOption {
 :::
 
 ::: {#ex-option-declaration-eot-backend-gdm .example}
-**Example: Extending `services.xserver.displayManager.enable` in the `gdm` module**
+### Extending `services.xserver.displayManager.enable` in the `gdm` module
 ```nix
 services.xserver.displayManager.enable = mkOption {
   type = with types; nullOr (enum [ "gdm" ]);
@@ -236,7 +240,7 @@ services.xserver.displayManager.enable = mkOption {
 :::
 
 ::: {#ex-option-declaration-eot-backend-sddm .example}
-**Example: Extending `services.xserver.displayManager.enable` in the `sddm` module**
+### Extending `services.xserver.displayManager.enable` in the `sddm` module
 ```nix
 services.xserver.displayManager.enable = mkOption {
   type = with types; nullOr (enum [ "sddm" ]);
diff --git a/nixos/doc/manual/development/option-types.section.md b/nixos/doc/manual/development/option-types.section.md
index 51977c58333..9e2ecb8e356 100644
--- a/nixos/doc/manual/development/option-types.section.md
+++ b/nixos/doc/manual/development/option-types.section.md
@@ -36,7 +36,7 @@ merging is handled.
     together. This type is recommended when the option type is unknown.
 
     ::: {#ex-types-anything .example}
-    **Example: `types.anything` Example**
+    ### `types.anything`
 
     Two definitions of this type like
 
@@ -356,7 +356,7 @@ you will still need to provide a default value (e.g. an empty attribute set)
 if you want to allow users to leave it undefined.
 
 ::: {#ex-submodule-direct .example}
-**Example: Directly defined submodule**
+### Directly defined submodule
 ```nix
 options.mod = mkOption {
   description = "submodule example";
@@ -375,7 +375,7 @@ options.mod = mkOption {
 :::
 
 ::: {#ex-submodule-reference .example}
-**Example: Submodule defined as a reference**
+### Submodule defined as a reference
 ```nix
 let
   modOptions = {
@@ -403,7 +403,7 @@ multiple definitions of the submodule option set
 ([Example: Definition of a list of submodules](#ex-submodule-listof-definition)).
 
 ::: {#ex-submodule-listof-declaration .example}
-**Example: Declaration of a list of submodules**
+### Declaration of a list of submodules
 ```nix
 options.mod = mkOption {
   description = "submodule example";
@@ -422,7 +422,7 @@ options.mod = mkOption {
 :::
 
 ::: {#ex-submodule-listof-definition .example}
-**Example: Definition of a list of submodules**
+### Definition of a list of submodules
 ```nix
 config.mod = [
   { foo = 1; bar = "one"; }
@@ -437,7 +437,7 @@ multiple named definitions of the submodule option set
 ([Example: Definition of attribute sets of submodules](#ex-submodule-attrsof-definition)).
 
 ::: {#ex-submodule-attrsof-declaration .example}
-**Example: Declaration of attribute sets of submodules**
+### Declaration of attribute sets of submodules
 ```nix
 options.mod = mkOption {
   description = "submodule example";
@@ -456,7 +456,7 @@ options.mod = mkOption {
 :::
 
 ::: {#ex-submodule-attrsof-definition .example}
-**Example: Definition of attribute sets of submodules**
+### Definition of attribute sets of submodules
 ```nix
 config.mod.one = { foo = 1; bar = "one"; };
 config.mod.two = { foo = 2; bar = "two"; };
@@ -476,7 +476,7 @@ Types are mainly characterized by their `check` and `merge` functions.
     ([Example: Overriding a type check](#ex-extending-type-check-2)).
 
     ::: {#ex-extending-type-check-1 .example}
-    **Example: Adding a type check**
+    ### Adding a type check
 
     ```nix
     byte = mkOption {
@@ -487,7 +487,7 @@ Types are mainly characterized by their `check` and `merge` functions.
     :::
 
     ::: {#ex-extending-type-check-2 .example}
-    **Example: Overriding a type check**
+    ### Overriding a type check
 
     ```nix
     nixThings = mkOption {
diff --git a/nixos/doc/manual/development/settings-options.section.md b/nixos/doc/manual/development/settings-options.section.md
index 476ba4b03f9..5060dd98f58 100644
--- a/nixos/doc/manual/development/settings-options.section.md
+++ b/nixos/doc/manual/development/settings-options.section.md
@@ -143,7 +143,7 @@ These functions all return an attribute set with these values:
     :::
 
 ::: {#ex-settings-nix-representable .example}
-**Example: Module with conventional `settings` option**
+### Module with conventional `settings` option
 
 The following shows a module for an example program that uses a JSON
 configuration file. It demonstrates how above values can be used, along
@@ -218,7 +218,7 @@ the port, which will enforce it to be a valid integer and make it show
 up in the manual.
 
 ::: {#ex-settings-typed-attrs .example}
-**Example: Declaring a type-checked `settings` attribute**
+### Declaring a type-checked `settings` attribute
 ```nix
 settings = lib.mkOption {
   type = lib.types.submodule {
diff --git a/nixos/doc/manual/development/writing-modules.chapter.md b/nixos/doc/manual/development/writing-modules.chapter.md
index ae657458d76..e07b899e6df 100644
--- a/nixos/doc/manual/development/writing-modules.chapter.md
+++ b/nixos/doc/manual/development/writing-modules.chapter.md
@@ -37,7 +37,7 @@ options, but does not declare any. The structure of full NixOS modules
 is shown in [Example: Structure of NixOS Modules](#ex-module-syntax).
 
 ::: {#ex-module-syntax .example}
-**Example: Structure of NixOS Modules**
+### Structure of NixOS Modules
 ```nix
 { config, pkgs, ... }:
 
@@ -100,7 +100,7 @@ Exec directives](#exec-escaping-example) for an example. When using these
 functions system environment substitution should *not* be disabled explicitly.
 
 ::: {#locate-example .example}
-**Example: NixOS Module for the "locate" Service**
+### NixOS Module for the "locate" Service
 ```nix
 { config, lib, pkgs, ... }:
 
@@ -161,7 +161,7 @@ in {
 :::
 
 ::: {#exec-escaping-example .example}
-**Example: Escaping in Exec directives**
+### Escaping in Exec directives
 ```nix
 { config, lib, pkgs, utils, ... }: