Hacking Session, Day 4

Stuff worked on during the hacking session on day 4:

• g5pw@: Work on a better HTML port index
  ​https://github.com/g5pw/macports-port-tree, eventually to be deployed at ​https://tree.macports.org/
• cal@: Add per-chapter and per-section tables of contents to the guide
  ​https://github.com/macports/macports-guide/pull/14
• raimue@: Remove documentation from github port group
  ​https://github.com/macports/macports-ports/9ebf8f61b0a26cb0e1559df1710a50b793462f68