Improve docs: why do we ignore almost all the FP jargon in this project

- [ ] Describe our decision
- [ ] Add a link to: https://github.com/jmesyou/functional-programming-jargon.py
- [ ] Improve https://github.com/jmesyou/functional-programming-jargon.py with `returns` links and examples

Start by reading the issue checklist and the linked functional-programming-jargon.py repository. Document why this project omits most FP jargon, add the requested link, and improve the jargon repository with returns links and examples; done means all three checklist items are addressed.

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