Fix indentation rule for dart.kak

rc/filetype/dart.kak

@@ -97,6 +97,8 @@ define-command -hidden dart-indent-on-new-line %~
         try %[ execute-keys -draft k<a-x> <a-k> ^\h*(case|default).*:$ <ret> j<a-gt> ]
         # indent after if|else|while|for
         try %[ execute-keys -draft <semicolon><a-F>)MB <a-k> \A(if|else|while|for)\h*\(.*\)\h*\n\h*\n?\z <ret> s \A|.\z <ret> 1<a-&>1<a-space><a-gt> ]
+        # deindent closing brace when after cursor
+        try %[ execute-keys -draft <a-x> <a-k>^\h*\}\h*$<ret> hm <a-S> 1<a-&> ]
     =
 ~