Make josh codeowner of keyboard files (#2204)

## 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

Author: pokey

.github/CODEOWNERS

@@ -1 +1,4 @@
 *       @pokey @AndreasArvidsson
+
+*keyboard* @pokey @josharian
+*Keyboard* @pokey @josharian