Update overlay

Author: John Yorke

_config.yml

@@ -59,7 +59,7 @@ topbar_title_color                        : "#ffffff"
 
 cover_image                               : assets/headerimage.jpg                    # Replace with alternative image path or image URL.
 cover_overlay_color                       : "#000000"
-cover_overlay_transparency                : 0.0
+cover_overlay_transparency                : 0.3
 
 device_color                              : black                                     # Set to: blue, black, yellow, coral or white.