Build improvements (#591)

* HtmlGenerator: Load converters lazily

This is a workaround so that .NET 6 apps can use the .NET FW
build of monodoc.dll without worrying about TypeInitializationExceptions
for converters they don't use.

* Fix netstandard2.0 compatibility

* Replace SharpZipLib submodule with package reference

Remove mdoc/packages.config as well.

* Bump Lucene.Net.Light to latest version to support NetStandard

* monodoc: Change to SDK-style project

* monodoc: Move to netstandard2.0

* Replace all packages.config with PackageReference

Bump mdoc.Test.FSharp.fsproj to .NET 4.7.1 to fix issues using
System.ValueTuple.

* Adjust to mdoc.Test.FSharp.fsproj bump to v4.7.1

* mdoc.Test.FSharp.fsproj: Convert to SDK-style

Fixes errors building in VS2022.

* mdoc.Test.csproj: Update to SDK-style too

* mdoc.Test.csproj no longer needs a direct FSharp.Core reference

* mdoc.Test.FSharp.fsproj: Fix FSharp.Core reference

https://github.com/dotnet/fsharp/blob/main/docs/fsharp-core-notes.md#how-to-explicitly-reference-fsharpcore

* mdoc.Test.csproj: Restore manual WPF reference

* Use AppendTargetFrameworkToOutputPath to avoid touching Makefiles

* Update en.expected-fsharp/index.xml

2 files changed, 0 insertions, 0 deletions

diff --git a/external/Lucene.Net.Light b/external/Lucene.Net.Light
-Subproject 85978b7eb94738f516824341213d5e94060f528
+Subproject 68fa3260b0bb497ed80b4b383e71862bf519c05
diff --git a/external/SharpZipLib b/external/SharpZipLib
deleted file mode 160000
-Subproject 9ad7f5845222c99ff009a1daddedc051d25a06b