Adding `# :nodoc:` to the parent `class` / `module` is not going
to ignore nested classes or modules.

There is a modifier `# :nodoc: all` but sadly the containing class
or module will continue to be in the docs.

/cc @sgrif

As we promote these classes to first class concepts, these classes are
starting to gain enough behavior to warrant being moved into their own
files. Many of them will become quite large as we move additional
behavior to the type objects.