Improve default README

I recreated the default README using some projects as inspiration... The main goal was to make every section more clear and focus on the project dependencies & integration process.

One of the new "features" is that we now have recording examples, like:

* http://showterm.io/6a0054fb8b6b53a56ef2c#slow
* http://showterm.io/a4f25718904e532b321ad#slow

Close #280