Documentation on links, pipelines, fieldMetadata and more insufficient

[nyteshade]

I really wanted to use this because the plumbing seems extensive enough and because you've solved several features like custom scalars; that being said, I have spent too many days both converting TypeScript to JavaScript in my head (not a super big deal, but causes some issues), reading through code that has far too few comments, and all this because the documentation is lacking.

Please provide better docs. For now we are using Apollo's schema stitching until this becomes a bit more fleshed out.

Wish list

• better docs on pipelines
• better docs on links
  • better docs on fieldMetadata
• full SDL of the example linked stitched schemas in the README.md examples
• ways to have a type in schema B implement an interface defined in schema A