API Docs "View Source" link broken

[tig]

I added support for View Source via docfx in #1914, but it didn't get enabled in main until I merged #1955 into main just now.

However, because Docfx always uses `'git config --get remote.origin.url' to determine the URL (see dotnet/docfx#1544), the link is broken.

I believe the right way to fix this is to address #1745.