Docs: F# 5 docs update

[cartermp]

This tracks work to update the docs site with F# 5 content:

• [x] "What's new in F# 5" article, with index update
• [x] Update most uses of sprintf to use interpolated strings, particularly in "What is F#?" and the F# Tour
• [x] Ensure coherency in the installation of "get started" pages
• [x] Language reference: interpolated strings - new article
• [x] Language reference: nameof - new article
• [x] Language reference: open type declarations - update open article
• [ ] Language reference: applicative computation expressions - update CE article
• [x] Language reference: quotations retain constraints - update quotations article
• [x] Language reference: slices behavior for negative/nonexistent ones, fixed-index 3d and 4d slices - update slices article
• [x] Language reference: default interface member consumption - update interfaces article
• [x] Language reference: nullable value types - new article
• [x] F# Interactive: emphasize package references

[dburriss]

@cartermp I would be interested in helping out. Are there guides on recommended structuring of docs or something like that?

[cartermp]

@dburriss thanks for offering! No real recommended structure, but for things like language reference articles I will typically copy-paste another similar article and then tweak it from there. Usually the right structure falls out of that.

[dburriss]

Sorry @cartermp I had some other writing due Monday and looks like mostly done now.

[luisquintanilla]

@cartermp I can take these

• Slices (https://docs.microsoft.com/en-us/dotnet/fsharp/language-reference/slices)
  
  
  
  • How to make this article more beginner friendly
  
  
• F# Interactive (https://docs.microsoft.com/en-us/dotnet/fsharp/tutorials/fsharp-interactive/) Collaborating with @AngelMunoz
  
  
  
  • Better samples?
  
  
  • Better guidance?
  
  
  • Better organization of the topic?
  
  
  • Better title?
  
  

[AngelMunoz]

After reviewing the FSI document in the session call I took the following notes

• Move fsharp-interactive into a Tools section for the F# docs
  
  
  
  • Requires updating toc.yml and index.yml
  
  
  • Add (if possible, not required) any kind of tutorial or walkthrough like in the tutorials section that uses the FSI
  
  

cc @luisquintanilla @dsyme @cartermp
I got my fork running I'll try to get a PR in the following days, Luis let me know how should we coordinate this in case you have feedback on the original article

[lqdev]

@AngelMunoz you can open a PR against this repo and I can take a look.