Fix/code cleaning

- Moves homepage viz sections into includes for easier maintenance 
- Remove unused code
- Cleans spacing
- Cleans bottom-of-page scripts and moves them all into `scripts.html`
- Uses Jekyll to load scripts based on location (much of our js is only used on one page)
- Replaces sector commodity icons with svg sprite font used in map
- Adds aria info for svgs
- Reworks footer to be more useful. It also better matches the emerging Webmaker footer project standard
- Fixes broken links to office images
- Removes old section break code, as that is no longer in the design