* [fix/html-serializer-docs-add-class-name-example] add example to the HTML serializer docs on how to use element attributes when serializing and deserializing. I spent a lot of time figuring this out myself so hopefully will save others from having to go through the same process!
* [fix/html-serializer-docs-add-class-name-example] Fix linting errors with Prettier
* Fix spell check bug by add data-text:true
* Fix spell check bug by spell check add length to a leaf
* Fix tests to use data-text:true for marks
* Rename data-text to data-slate-leaf; Remove setRef; unlift attributes in leaf
* Update examples with data-*
* Add attributes to document
* Fix renderMark in all documents
* Prettier markdown
* rename state to value in slate core, as deprecation
* rename all references to state to value in slate core
* migrate slate-base64-serializer
* migrate slate-html-serializer
* migrate slate-hyperscript
* migrate slate-plain-serializer
* migrate slate-prop-types
* migrate slate-simulator
* fix change.setState compat
* deprecate references to state in slate-react
* remove all references to state in slate-react
* remove `value` and `schema` from props to all components
* fix default renderPlaceholder
* fix tests
* update examples
* update walkthroughs
* update guides
* update reference
* Replace cheerio with parse5
* Convert to dependency injection for HTML parser
* Add options.domParser to HTML serializer
* Fallback to native DOMParser if present and no option provided
* Error if no DOM parser is available (option or native)
* Update tests to pass parse5 as config option
* Update test so it passes.
Cheerio interprets `<p><hr /></p>` as one `p` node with a child `hr`
node, but both parse5 and native DOMParser interpret it as 3 nodes: a
blank `p` node, `hr` node, and second blank `p` node. Update test
expectation to match new API.
* Remove cheerio-esque compatibility conversion.
* Use `application/xml` in native DOMParser
Using `text/html` causes it to wrap the fragment in html, body, etc
* Change error message to single line.
Was inserting an undesired newline char
* Add documentation for new `domParser` option to html serializer
Also boyscout missing documentation for `defaultBlockType` option
* Rename `domParser` option to `parseHtml`
Rename the option to make it clearer what it does, since it accepts a
function and not a `DOMParser` analogue object.
