Revise documentation for .net 5 release

[AndrewIOM]

Description

The current documentation website https://fslab.org/RProvider/ refers to use of the 1.x type provider on .net framework and mono and pre-dates .net core. The documentation should be updated now that we no longer support mono and .net framework, and only support .net 5+.

Error messages, screenshots

None

Failing test, failing GitHub repo, or reproduction steps

N/A

Expected Behavior

The website should be able to direct users:

• [x] How to access the package from FSI using the new nuget reference format
• [x] Link to release notes and github repo
• [x] Explain how to set R_HOME as a pre-requisite to use package
• [x] Get rid of the out-of-date mac / linux guidance

Known workarounds

NA

Other information

• Operating System:
  • [ ] windows [insert version here]
  • [ ] macOS [insert version]
  • [ ] linux [insert flavor/version here]
• Platform
  • [ ] dotnet core / v5+
  • [ ] dotnet framework (NB legacy support only)
  • [ ] mono (NB legacy support only)
• Branch or release version:

[dsyme]

I did a small amount of work on the docs in #230

[saerosV]

I believe this issue could be closed, @AndrewIOM. The home and requirements pages all seem to be updated, along with the file provided in this System requirements section.

[AndrewIOM]

Thanks - yes this work appears to have already been completed. Thanks for spotting!