Rich Text Editor Component

We ideally have a WYSIWYG rich text editing component that can import/export Markdown or similar format.

See [this wiki entry](https://github.com/dashkite/wiki/blob/349f9aa2b92092fbb877d9ac1a25d1b504f53c88/docs/journal/2024/0803-rich-text-editors.md) for a summary of efforts to use existing implementations and recommendations for the best way to satisfy this requirement.