Bug Fix: Fix Add New link for styles when editing a region

This is a simple issue & simple fix. The “Add New” link for adding a new highlight style when editing a region goes to the incorrect URL. Meanwhile the Highlight Styles page & its functionality is working fine.

All that’s involved is editing the imagemapper.php replacing edit.php?post_type=imagemap_area&page=imagemapper.php with edit.php?post_type=imagemap_area&page=imagemap-area-styles.

I’d love to see this officially implemented in the plugin. Also, as I’ve stated in https://wordpress.org/support/topic/bug-fix-need-latest-version-of-imagemapster-script-to-prevent-jquery-issue/ (another bug fix that hasn’t been patched into the plugin after more than a year), it would be nice to have this plugin listed on GitHub (or similar) so patches can be suggested and adopted much quicker & easier considering the limited development for this plugin currently.