Add test to keep grammar-list synced with submodules (#3793)

* Add test to check if grammar list is outdated

* Update grammar list

* Fix duplicate punctuation in error messages

script/list-grammars

@@ -99,4 +99,8 @@ class GrammarList
 end
 
 list = GrammarList.new
-list.update_readme()
+if ARGV.include? "--print"
+  puts list.to_markdown
+else
+  list.update_readme
+end