Proposal: Use typescript types to fill in API docs

[flotwig]

We could use the typescript docs from the cypress repo to potentially autofill some of our API docs for us.

typedoc can generate machine-readable and HTML documentation from our .ts files.

Things that would have to be figured out:

• How does docs release work? How is this versioned against cypress repo?
  • Deploy docs after latest types are available on cypress master branch?
• What level of docs could be replaced by this?
  • Probably shouldn't put our entire API docs in Typescript
  • Would be nice to pull call signatures, property descriptions, default values
  • Could also pull examples from the docs - @example tags
  • Could add partials to existing .md docs: {% call-signatures "cy.request" %}, {% properties "Cypress.RequestOptions" %}
• Should we host typedoc's HTML output and link to it whenever types are mentioned in the docs?

I have typedoc generating type info and some basic tags here: #2112