See #14. Add JSON support.

JSON is processed as if it were JavaScript.
I have tested it (see examples/simple-jsbeautifyrc/test.json)
and it works as expected and supports comments!

examples/simple-jsbeautifyrc/test.json

@@ -0,0 +1,9 @@
+{
+  "indent_size": 2,
+"indent_char": " ", // test
+  "indent_level": 0,
+"indent_with_tabs": false, /* test */
+  "preserve_newlines": true,
+"max_preserve_newlines": 2, /* test *
+  "jslint_happy": true
+}

lib/atom-beautify.js

@@ -244,6 +244,9 @@ function beautify() {
   }
 
   switch (editor.getGrammar().name) {
+  case 'JSON':
+    // Treat JSON as JavaScript, because it will support comments.
+    // And Glavin001 has tested JSON beauifying with beautifyJS.
   case 'JavaScript':
     text = beautifyJS(text, getOptions('js', allOptions));
     break;