Add CmdPal debugging information (#48108)

## Summary of the Pull Request
Adding information about using the Command Palette Visual Studio
solution filter based on
https://github.com/microsoft/PowerToys/issues/47997#issuecomment-4524045763.

## PR Checklist

- [ ] Closes: #47997 

## Detailed Description of the Pull Request / Additional comments
I found this really useful and couldn't see a reference to it anywhere
else in the devdocs. Not sure if this is the best way to describe the
process, but I think adding this information somewhere in the debugging
doc would really help newcomers to CmdPal development!