RESTRUCTURE: BSSw PSIP Website

[mrmundt]

The structure for https://bssw-psip.io could use some improvement. This issue is to track suggestions I have on how to make it more sustainable and maintainable, as well as more user friendly:

• Better/more clear Development & Maintenance documentation (README: Simple Developer Documentation #1 is a start in this direction; BUG FIX: Table of contents update script should ignore metadata line ptc-catalog#45 could have been avoided if we had better docs)
• Convert subsites (Practice guides, PTCs) into true Jekyll sites
• Standardize formatting of main site and subsites
• Make links back and forth before the main and subsites (e.g., accessible in both directions)
• Add tests for automated processes (e.g., auto-generation of table of contents scripts)
• Proofread existing content for errors / typos / incomplete information