Discussing/moving any of these forward is a big help.
### Docs
- build the contributor/dev guide from CONTRIBUTING.md plus the READMEs; clean up
- move general PTA docs to plaintextaccounting.org
- simplify manuals' TOC/structure on the website
### Tests
- migrate to tasty, unblock ghc 8.8 support
- survey/document current testing setup (process, coverage, redundancy..); identify weaknesses; design a policy for tests; make a plan for achieving that
- start adding property tests/other new kinds of testing if appropriate