* Upstream Zod error map improvements from Starlight
* Update tests
* Use Zod error map when validating user config
* Update user config error formatting for error map
* Tweak colours
* Separate colour and indentation steps for clarity
* Fix broken link to experimental flag documentation
* Add changeset
* Update tests
* Fix one more test
* Use existing utility for bold and other Markdown formatting
* Extract codeRegex to top level
* Don’t dim text and tweak indentation
