Clean up generated output

[julianbenegas]

• all of the generated stuff needs to go below a generated directory, and an index on the outer scope will link to it
• we want to just generate javascript and d.ts, instead of valid typescript + javascript. just the declarations file.
• do we need schema.graphql?
• we want to create a fragments.{js,ts} file with common fragments (just two or three) as a demo of how to create more in the future