Merge branch 'docs-markdownlint-rule-removal' into 'master'

Enable code fence check in markdownlint

See merge request gitlab-org/gitlab!28627

.markdownlint.json

@@ -124,6 +124,5 @@
       "YouTrack"
     ],
     "code_blocks": false
-  },
-  "code-fence-style": false
+  }
 }