Tweaked UI

- Looks more like jumbotron narrow (although I'm not sure how well this
will work, especially as you can see the row at the top isn't the same
size as the items below it. I'm probably doing something wrong here, but
trying to link to the jumbotron-narrow.css in index.html isn't working,
I get an error....)
- Spaced the menu items apart. Ideally they will be evenly spaced apart
but I've run into the problem where resizing the window makes the items
stack. I would like to make the website resizable but that will require
some reworking.