Add a default mapping for `:LeanRestartFile` and related tips

[utensil]

Zulip

• [x] Add a default mapping for :LeanRestartFile
  • [x] stylua
  • [ ] test
• [x] Add related tips, restart file, restart server
  • [ ] review wordings

[Julian]

Thanks! The style warning is markdownlint being silly, we only care about GitHub's parser. The wordings actually look fine to me too -- if you do care to add a test it should be pretty trivial to do so although we don't actually test all the mappings we set really currently, we just pick some single one and make sure it's properly mapped -- so I'm happy to merge this as-is and add a linter exception -- if you do have any other suggestions or improvements on this or anything though they're always welcome!

[utensil]

Thanks, I'll try to figure out how to set up the test tomorrow, and add the test.

[utensil]

Updated and tested locally from nvim, it seems to work!