Add support for [[wiki-style]] links in markdown (#9275)
* Add support for [[wiki-style]] links in markdown
1. Support for [[wiki-style]] links ensures that they do not get broken
by the prettier formatting by being wrapped over multiple lines.
2. The contents of the link (between the `[[]]` brackets) are treated
as raw text. This is because the various tools that rely on the
`[[]]` syntax do not agree on what is allowable between them.
* Add a changelog document
* Update pr-9275.md
* Add additional tests as requested
* Add a fix for AST tests
* Fix issues with prose-wrap: "preserve"
* Lint
* Add a clean action for wikiLinks
Co-authored-by: fisker Cheung <lionkay@gmail.com>
