feat(gatsby-transformer-documentationjs): support linking typedefs

[pieh]

There is some breaking changes here so will require major version bump

Added features:

• added support for linking typedef/callback to property/param/variable types - this allows defined type once and reusing it in multiple instances
• added support for members:
  for example

  const object = {
    /**
      * description of static member
      * @type {string}
      */
    thisIsAMember: true
  }

  there are a lot more types of members (i.e class members etc) that are also supported in this PR
• added support for optional properties:

  /**
   * @property {number} [nameOfOptionalField] desc
   */
  const object

  this was there before but it was tucked in type information making it much harder to use nicely
  this PR sets optional field (true/false) in documentation nodes and moves type information up to not have to handle this in frontend code
  this is BREAKING CHANGE
• added support for @deprecated field
• params, properties and returns fields get transformed into separate DocumentationJS nodes - those fields contain subset of DocumentationJS fields, but it's super nice for defining reusable fragments for types (and typedefs)
  this is BREAKING CHANGE if someone was using fragments for those fields - but this might be unlikely anyone actually did because GraphQL type name was generated dynamically during schema inference so it might change between builds, if fragments weren't used there is no need to change anything (i.e. our queries on www don't require any changes)

TODO: bump documentation package version - we are 2 major versions behind latest - from their changelog it doesn't seem like there are any breaking changes that would affect us, but need to validate that