Added about section to README.md

Added explanation of where the project is right now and the long term vision.

Why is this needed? Personally, when I did my first pull request, I was a bit sceptical about the selected publishing solution: a plain HTML file served as a GitHub page. I felt that it was not going to cut it in the long run. I only like to contribute to a project that I believe in and that seems capable of surviving.

Now that I know that this is only the experimenting start, I'm happy to contribute some more. 

Hopefully the About info can convince some one else. Feel free to update/replace my text with something more apropriate.