Beagle-style: Start work on the generic styles for the sidebar

[RichardLitt]

Started in BeagleLab/beagle-style.

• [x] Init repository
• [x] Install gulp and get sass to minified css working
• [x] Copy over less file from sci-nav prototype0
• [x] Convert current Beagle style into prototype0 style

[RichardLitt]

Work has been started. What's left is forming a consistent format for output, css. We'll get there organically, no need for this card anymore.