Update readme + first working grunt watch/serv!

Updated a whole bunch of stuff. Updated readme. Installed node modules:

* grunt-autoprefixer
* grunt-contrib-jshint
* grunt-contrib-sass
* grunt-contrib-uglify
* grunt-contrib-watch
* grunt-jekyll
* grunt-shell
* grunt-svgstore
* load-grunt-tasks

 and first working grunt task with ‘grunt serve’ & ‘grunt watch’