doc: add lint rule to enforce trailing commas

PR-URL: #45471
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

Author: aduh95

doc/.eslintrc.yaml

@@ -15,3 +15,4 @@ rules:
 
   # Stylistic Issues
   no-multiple-empty-lines: [error, {max: 1, maxEOF: 0, maxBOF: 0}]
+  comma-dangle: [error, always-multiline]