Develop better demo application

[rochacbruno]

The demo app is in https://github.com/rochacbruno/Flask-GoogleMaps/tree/master/examples

Accessible in: http://flaskgooglemaps.pythonanywhere.com

The page currently is very simple and needs improvements.

• [ ] Better layout (simple, yet beautiful) (example: https://jz6.github.io/PoGoMap/ )
• [ ] A menu bar to handle project links (repo, chat, issues etc)
• [ ] mobile enabled (responsive)
• [ ] split the demo into different views (one per map with links in menu bar)
• [ ] Put better code example below each map, with (html + python) tabs and code highlight (maybe using embedded gist)
• [ ] A section "who uses fgmaps" including https://github.com/AHAAAAAAA/PokemonGo-Map
• [ ] Include Flask-Caching in demo app views