* Replace `renderers` w/ `components`
* Replace `allowNode` w/ `allowElement`, which is now given a hast
  element (as the first parameter)
* Replace `allowedTypes` w/ `allowedElements`
* Replace `disallowedTypes` w/ `disallowedElements`
* Change signature of `linkTarget` and `transformLinkUri`, which are now
  given hast children (as the second parameter)
* Change signature of `transformImageUri`, which is now given the `alt`
  string as the second parameter (instead of the fourth)
* Replace `plugins` w/ `remarkPlugins` (backwards compatible change)
* Add `rehypePlugins`
* Change `includeNodeIndex` to `includeElementIndex`: it still sets an
  `index`, but that value now represents the number of preceding elements,
  it also sets a `siblingCount` (instead of `parentChildCount`) with
  the number of sibling elements in the parent
* The `columnAlignment` prop is no longer given to table elements:
  it’s available as `style` on `th` and `td` elements instead
* The `spread` prop is no longer given to list elements: it’s already
  handled

* If you want HTML, add [`rehype-raw`](https://github.com/rehypejs/rehype-raw)
  to `rehypePlugins` and it’ll work without bugs!
* Remove `allowDangerousHtml` (previously called `escapeHtml`) option:
  pass `rehype-raw` to allow HTML instead
* Remove `with-html.js`, `plugins/html-parser.js` entries from library
* Remove naïve HTML parser too:
  either use `rehype-raw` to properly support HTML, or don’t allow it at all

Co-authored-by: Christian Murphy <christian.murphy.42@gmail.com>