Intellisense performance guide for users

Could we have a guide for users on how to maximize intellisense performance? For example:
- Does splitting long files into smaller ones improve intellisense performance?
- Does closing open files improve performance?
- Does unloading projects improve performance?
- Do explicit type annotations help performance?
- Does splitting large projects into smaller ones help or hurt performance?
- Does putting objects in previous files/in the same file outside of scope (with more local scopes or with access modifiers) help performance?

Related to: https://github.com/dotnet/fsharp/issues/2964