vscode: Recommend ruff extension (#1833)

We added `ruff` in #1375. There's a corresponding VSCode extension by
the author, so probably a good idea to use it to surface lints earlier
than pre-commit.

https://github.com/astral-sh/ruff-vscode

## Checklist

- [ ] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [ ] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [ ] I have not broken the cheatsheet

---------

Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

Author: auscompgeek

.vscode/extensions.json

@@ -3,6 +3,7 @@
   // for the documentation about the extensions.json format
   "recommendations": [
     "AndreasArvidsson.andreas-talon",
+    "charliermarsh.ruff",
     "dbaeumer.vscode-eslint",
     "esbenp.prettier-vscode",
     "jrieken.vscode-tree-sitter-query",