merkle: first go at types
first draft of the CONTRIBUTE.md file
docs: add section about becoming a contributor

- add git workflow and license paragraphs
- state resource PPSP as wip
- added committers workflow
Update CONTRIBUTE.md

corrected typos.
docs: templates, clean up

- add erlang template for new files
- update, wrap to 80 chars, indent, add tests and indentation
- rename to CONTRIBUTING.md so pull reqs have a useful link
build: add targets for (dist)clean and commit
types: include atoms & typespecs matching IETF RFC