Missing mapping with ToDocs command

[pavelsavara]

When I worked on dotnet/dotnet-api-docs#7129 the DocsPortingTool didn't map some methods to xml files. I had to do it manually.

• M:System.Net.Http.HttpRequestOptions.TryGetValue``1(System.Net.Http.HttpRequestOptionsKey{``0},``0@)
• M:System.Net.Http.HttpRequestOptions.Set``1(System.Net.Http.HttpRequestOptionsKey{``0},``0)

The command I used was DocsPortingTool -Direction ToDocs -Docs c:\Dev\dotnet-api-docs\xml -IntelliSense C:\dev\runtime\artifacts\bin\System.Net.Http\ -IncludedAssemblies System.Net.Http -IncludedNamespaces System.Net.Http -Save true on this code https://github.com/dotnet/runtime/pull/58896/files