Add shell check pre commit hook

[pokey]

Checklist

• [ ] I have added tests
• [ ] I have updated the docs and cheatsheet
• [ ] I have not broken the cheatsheet

[fidgetingbits]

Likely worth adding a playground exclude for this too, since the playground file from https://github.com/cursorless-dev/cursorless/pull/2058 will probably fire a bunch too

[auscompgeek]

data/playground/ is already excluded in the pre-commit config globally