Update styles

- add bootstrap's grid
- update the colors
- update the padding
- try to update some font sizes
- remove unneeded styles
- remove some unneeded markup

There's still a lot to do, but this is a start. Some things that aren't
in comments below:
- remove now unused classes
- double check everything
- check it on mobile
- check it in other browsers
- center the 'push with leiningen' text
Remove unneeded attribute

text/javascript is assumed if not present:
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script#Attributes
Finish up the dashboard page

- use the grid system for hero text, but reflow the text on small
screens
- transition navigation/recent jar colors
- disallow blank searches
- pad the recent jars link so you can click the whole box
- fix up the padding and text-sizes a bit (these are still probably off)
- fix up the colors a lit (these are probably still off)
- use the grid on more screen types (to not immediately snap to one
column when the screen gets smaller)
- remove the search button for smaller screens
- vertically center the navigation and add a background color on hover