Adds pages and data for the PIF program

Most significant changes:
- Make projects.json into yml, with data about PIF projects.
- Add PIFs, past and present, to the team.yml file (but hidden from front page for now)
- `pif_bare` layout for PIF pages
- New pages about PIFs and PIF projects categorized by round
- Updated team loop to alphabetize the data for us. Now team members can be added by simply inserting new data at the bottom of the file