Fix invalid xref links in dotnet-api-docs

[gewarren]

Check any build report to see the warnings.

[mairaw]

Should this be in the dotnet-api-docs repo then?

[gewarren]

Should this be in the dotnet-api-docs repo then?

I couldn't decide where to put it, but happy to move it there. I created it here so I could it add it to the July project and track my work in one place.

[mairaw]

Makes sense!

[mairaw]

I also found broken links like the ones in dotnet/dotnet-api-docs#4527 where the formatting made them not be recognized as links. Not sure how to find those in the content. I found them by accident while doing the Try .NET work,

Maybe search to find more \<xref: occurrences to see if there's more.

[mairaw]

I guess there is 😢

[gewarren]

Remaining links:
bad-xrefs-0720.xlsx