docs: update path of release script

Author: MultisampledNight

MAINTAIN.md

@@ -3,10 +3,11 @@
 ## How to release
 
 1. Commit everything and push everything you want in the release
-2. Run `util/release.sh`
+2. Run `maintain/release.sh`
 3. Bump the version number in
   - `typst.toml`
   - `template/main.typ`
   - `README.md`
+4. Submit a PR to the typst/packages repo
 
 That's it!