Finally fixed the Chrome drag bug

For pretty much forever you couldn't drag obstacles, traps, etc. in Chrome.

This was a massive pain in the rear to track down and eventually turned out to
be the width being set on these items. I'm still not sure why, but meh, it's fixed.

Author: hobnob

VirtualGloomhavenBoard/wwwroot/scss/_board.scss

@@ -18,6 +18,10 @@ $hexHeight: 90px;
     }
 }
 
+.overlay {
+    width: auto;
+}
+
 .hex-mask {
     @include mixins.mask(url('/img/hex-mask.png'), alpha, top right, 90px);
 }