nixpkgs-plugin-update: include GitHub URL in add commits

When adding new plugins, include the GitHub repository URL in the commit
body. This provides immediate context about the source repository without
needing to look up the plugin definition.

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

pkgs/development/python-modules/nixpkgs-plugin-update/nixpkgs-plugin-update/src/nixpkgs_plugin_update/__init__.py

@@ -640,12 +640,21 @@ class Editor:
             autocommit = not args.no_commit
             if autocommit:
                 assert editor.nixpkgs_repo is not None
+
+                commit_message = "{drv_name}: init at {version}".format(
+                    drv_name=editor.get_drv_name(plugin.normalized_name),
+                    version=plugin.version,
+                )
+
+                if isinstance(pdesc.repo, RepoGitHub):
+                    github_url = (
+                        f"https://github.com/{pdesc.repo.owner}/{pdesc.repo.repo}"
+                    )
+                    commit_message += f"\n\n{github_url}"
+
                 commit(
                     editor.nixpkgs_repo,
-                    "{drv_name}: init at {version}".format(
-                        drv_name=editor.get_drv_name(plugin.normalized_name),
-                        version=plugin.version,
-                    ),
+                    commit_message,
                     [args.outfile, args.input_file],
                 )