call rwdImageMap() when initialized

https://jira.walmart.com/browse/USFEHP-1248

This resolves an issue where the image maps were not automatically resizing on image load. Added a call to rwdImageMap() on initialization. Tested on the included index.html.

/cc @joshi0 @alexlande @geekdave @trombom @ryan-roemer
GLOBAL: Please reformat consistent with what the project / file already uses so we have everything lined up.