Fix indentation rule for json.kak

rc/filetype/json.kak

@@ -61,6 +61,8 @@ define-command -hidden json-indent-on-new-line %<
         try %{ execute-keys -draft k : json-trim-indent <ret> }
         # indent after lines beginning with opener token
         try %< execute-keys -draft k <a-x> <a-k> ^\h*[[{] <ret> j <a-gt> >
+        # deindent opener token(s) when after cursor
+        try %< execute-keys -draft <a-x> <a-k>^\h*[}\]]+\h*$<ret> hm <a-S> 1<a-&> >
     >
 >