Add Johannes' index page and improve structure of code

The buttons still have a weird blue color, thought they were supposed to be red? I used all the CSS files you sent me, Johannes - maybe something got lost along the way. Also added gitignore to get rid of temporary linux files. Improved structure of the code, i.e. put all CSS code in one file (main.css), split the presenter into two files - I suggest we use a separate presenter for each page. Also applied camelCase.