docs: add a friendly guide for users #70
Description
This came up in the discussion in #64 (comment)
The thing that got me into parser combinators was FParsec, and specifically the comprehensive user’s guide they have, which actually explains how you actually use them to write parsers.
Until this exists, the library can only be used by people who already know what a parser combinator is and how to use them. This is a shame, because parser combinators are a good solution for lots of real world parsing tasks.