docs: Update docs for using ESLint as the only formatter (#40679)

Closes #ISSUE

Release Notes:

- N/A

---------

Co-authored-by: Ben Kunkle <Ben.kunkle@gmail.com>

docs/src/languages/javascript.md

@@ -92,6 +92,7 @@ the formatter:
 {
   "languages": {
     "JavaScript": {
+      "formatter": [],
       "code_actions_on_format": {
         "source.fixAll.eslint": true
       }