Add documentation for packages about graphql-markdown

[edno]

This is a fair request and it would be a good opportunity for cleaning some of the interfaces.

I am also thinking about moving the graphql module into its own package.

I'll look into it in coming weeks.

@LunaticMuch - If you can share some details about your use case, then I will be able to prioritize and structure the doc the way it provides best value.

[edno]

@LunaticMuch - The packages documentation will be available this month, once the code has been migrated to TS.
I'll be doing this incrementally starting with @graphql-markdown/util and the upcoming @graphql-markdown/graphql.

[edno]

First package documented @graphql-markdown/utils 🥵

[edno]

Direct link to packages documentation: https://graphql-markdown.github.io/api/

In coming weeks, I'll add a quick start guide on how to create a custom app to generate docs from GQL using GraphQL-Markdown packages.