CONTRIBUTING.md: Move to repo root, where it is more visible.

We found that many users found it difficult to locate this document.

Github supports it in the root, see:
https://docs.github.com/en/communities/setting-up-your-project-for-healthy-contributions/setting-guidelines-for-repository-contributors

1 files changed, 2 insertions, 2 deletions

diff --git a/doc/contributing/submitting-changes.chapter.md b/doc/contributing/submitting-changes.chapter.md
index 29b8ec493e7..221ba300619 100644
--- a/doc/contributing/submitting-changes.chapter.md
+++ b/doc/contributing/submitting-changes.chapter.md
@@ -62,7 +62,7 @@
 
 - Push your changes to your fork of nixpkgs.
 - Create the pull request
-- Follow [the contribution guidelines](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md#submitting-changes).
+- Follow [the contribution guidelines](https://github.com/NixOS/nixpkgs/blob/master/CONTRIBUTING.md#submitting-changes).
 
 ## Submitting security fixes {#submitting-changes-submitting-security-fixes}
 
@@ -193,7 +193,7 @@ It’s important to test any executables generated by a build when you change or
 
 ### Meets Nixpkgs contribution standards {#submitting-changes-contribution-standards}
 
-The last checkbox is fits [CONTRIBUTING.md](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md). The contributing document has detailed information on standards the Nix community has for commit messages, reviews, licensing of contributions you make to the project, etc\... Everyone should read and understand the standards the community has for contributing before submitting a pull request.
+The last checkbox is fits [CONTRIBUTING.md](https://github.com/NixOS/nixpkgs/blob/master/CONTRIBUTING.md). The contributing document has detailed information on standards the Nix community has for commit messages, reviews, licensing of contributions you make to the project, etc\... Everyone should read and understand the standards the community has for contributing before submitting a pull request.
 
 ## Hotfixing pull requests {#submitting-changes-hotfixing-pull-requests}