Change Q# grammar repository

[ScottCarda-MS]

This PR updates the references for the Q# repository to use the modern Q# repo, replacing the now deprecated legacy Q# repo. This was done using the command script/add-grammar --replace qsharp-compiler https://github.com/microsoft/qsharp

Description

Checklist:

• [x] I am changing the source of a syntax highlighting grammar
  • Old: https://github.com/microsoft/qsharp-compiler
  • New: https://github.com/microsoft/qsharp

[ScottCarda-MS]

Is there an ETA as to when we might expect the next release to see this merged in?

[lildude]

I make a release approximately quarterly so it'll probably be in the next week or two.