fix: Adjacent JSX elements should be allowed in mdx (#6332)

* fix: adjacent JSX elements should be allowed in mdx

* chore: update CHANGELOG.unreleased.md for PR

* fix: adjacent JSX elements format issue of line

* fix: get html text from ast correctly

* fix: self closing issue

* fix: finally find out how to get original text from position

* chore: reset unnecessary changes

* fix: additional text after jsx should also be allowed

* fix: regression of empty text

* docs: add missing links

* fix linting...

.ignore

@@ -1,3 +1,2 @@
 website/static/lib
 dist
-