Updated the TOC in the README
+ Added `Package Management` to the TOC
Removed extra newlines in README
+ Removed extra newlines before the "Mobile" heading
Sorted lists in README
+ Sorted the list items alphabetically (in the README file)
Updated the README file
+ Moved the "Acappella" link out from the "Packages" heading to under a new "Package Management" heading
Updated the README file
+ Added the a link to "Acappella" under the Packages heading
+ Added the a link to "Sugar Cube Client" under the SDK heading
Reviewed-on: https://gitea.com/gitea/awesome-gitea/pulls/12
Reviewed-by: John Olheiser <john.olheiser@gmail.com>
Reviewed-by: 6543 <6543@noreply.gitea.io>
