Make Project Records editable on the ui

Allows CNCF Staff Members to update fields on the project records

Include in this change the following feedback from @riaankleinhans on the drift/diff page that diffs the maintainer records that the CNCF holds internally agains the publicly held files maintainer by Projects.

- Change the text of the "On Github" button that indidated that the maintainer record stored internally was founf on the current Project Admin file
- Make the Project Admin File more obviously a href to the file on the Project's repo
- Title the markdown rendered on the rhs of the diff page
- Make the buttons offering to add a maintainer to the maintainer-db more obvious - use CNCF Pink!