A plausible JSON comment.
```
[
  ["_comment", "README: Each resource format is a list with these values: mimetype, file_extension, readable_description"],
  ["application/x-director","DCR","Adobe Shockwave format"],
  ["ArcGIS Online Map", "ArcGIS Online Map", "ArcGIS Online Map"],
  ...
 }
```
Of course you'd need to tell the parser to strip off that line, but no great shakes.