Introduction guide

[Uriopass]

Some kind of introduction guide that helps a new player to create a small city like in the youtube demo.

Can be hosted on github's wiki and linked somewhere at the start.

[Uriopass]

https://github.com/Uriopass/Egregoria/wiki/Introduction-Guide

Should be enough to get most people started. It is quite short but to be honest there isn't much gameplay yet anyway.
I just need to add it in the game somwhere, like a "Help" button.