Emscripten - new html template - dark theme - hide console in Release

[ofTheo]

• Darker / modern theme for index.html
• Make no console / no header default. ie: just the app when built in Release.
• Allow for console / options with ?debug=1 in the url

Thoughts @Jonathhhan @NickHardeman

[Jonathhhan]

@ofTheo sounds all good to me.

[danoli3]

Also the template icon at the moment links to emscripten.com should this maybe link to openFrameworks.cc?