Add installation and running info

[mrkvon]

As far as my experience goes, it's necessary to:

1. clone the repository
2. npm install, bower install, ...

But I don't know what to do with Grunt and I have no desire to go through Grunt docs to find out.
A simple info about prerequisities, installation steps and running the app would go a long way.

❤️ 🔗 💻