pt-paper: Review abstract, some cleanup
pt-paper: Add introduction
pt-paper: Add Fundamentals intro
pt-paper: Add plain text section
pt-paper: Add version control section
pt-paper: Restructure outline

in particular:
- make it more hierarchical
- move "Extending" to a subsection of Conclusions
pt-paper: add Distributed Work section
pt-paper: add Editor and Engraver section
pt-paper: add Maintainability section
pt-paper: Slight restructuring of remaining sectiosn