fix link to pat-s/GitHub theme (#98)

Fixing the link to pat-s' theme repository.

Reviewed-on: https://gitea.com/gitea/awesome-gitea/pulls/98
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: pat-s <pat-s@noreply.gitea.io>
Co-authored-by: shamil <shamil@noreply.gitea.io>
Co-committed-by: shamil <shamil@noreply.gitea.io>

README.md

@@ -164,7 +164,7 @@ A curated list of awesome projects related to Gitea.
 * [Catppuccin](https://github.com/catppuccin/codeberg) - Soothing pastel theme for Codeberg (Easily modified to work with any Gitea instance)
 * [Modern](https://codeberg.org/Freeplay/Gitea-Modern) - Changes the layout for a more modern look. Usable with other themes that only change colors.
 * [theme.park](https://docs.theme-park.dev/themes/gitea) - Rich theme suite that includes Gitea
-* [pat-s/GitHub](https://github.com/pat-s/gitea-github-theme) - Opinionated GitHub-inspired light and dark themes
+* [pat-s/GitHub](https://codeberg.org/pat-s/gitea-github-theme) - Opinionated GitHub-inspired light and dark themes
 * [Sainnhe's Theme Pack](https://git.sainnhe.dev/sainnhe/gitea-themes) - Port of some editor themes
 
 ### Light