Updating HTML elements to map to their Aria 1.2 roles (#348)

* blockquote update

map to core aam blockquote role

* fix mapping for body/html

`html` should have mapped to `document` - this is now corrected and the table now indicates to refer to the WAI-ARIA mapping for the document role.

`body` no longer maps to `document` - which matches reality.  `body` now maps to `role=generic`.   further updates may be needed here for instances where authors incorrectly name a generic / provide the body with elements important to accessibility - e.g., `contenteditable`.

closes #330

* update section 3.4 introduction list

* remove bullet about “?” cells.  these have all been removed.
* update list item about `aria-roledescription` and mention that UAs must not expose the attribute if used on an implicit `generic` element.

* update aria 1.1 to 1.2 links

* update json data for specs

* update hgroup mapping to match reality

closes #331

* point to aria 1.2 roles

this PR updates the following elements to point to their implicit ARIA roles defined in core aam

* caption
* code
* del
* em
* ins
* meter
* paragraph
* strong
* sub
* sup
* time

* start marking generics

starts on issue #346, indicate some of the elements that will map to, or under certain conditions map to `generic`

* autonomous custom elements
* div
* form without accessible name
* form associated custom elements
* section without accessible name

* typo fixed

* Update index.html

Co-authored-by: Steve Faulkner <[email protected]>