Deprecating Forge #135

Hey,

Forge is basically deprecated due to multiple reasons - mostly connected to how .NET evolved with the introduction of dotnet CLI tool:

• dotnet new does project scaffolding better in a way that has become standard in .NET community
• dotnet add reference works out of the box
• Paket and FAKE works now as dotnet tools and again, it's a standard way of using such tools in .NET community.

Forge is still used in some cases by Ionide (moving files up/down in fsproj) but I'm planning to move those to our language server (FSAC).

I wouldn't recommend using Forge in 2020 - dotnet CLI does everything that's necessary for typical development workflow.