v0.22.0

Minor Changes

• 7537028 Thanks @constLiakos! - Combobox and ComboboxMulti gain allowCreate (+ optional createLabel):
  when the search term matches no option, an Add "term" row is offered
  (keyboard included) and picking it reports the raw trimmed term — for
  free-text entry into taxonomy-backed pickers.

• 2b7e756 Thanks @constLiakos! - RichTextEditor becomes hostable by full apps: extensions is now a full
  override of the built-in [StarterKit, Markdown] set (apps declare their
  complete extension set), and three composition props land — contentClassName
  (merged onto the editable region), onReady (editor instance on create,
  null on destroy — the app handle for commands and event wiring), and
  headingLevels (one toggle per level; labels.heading is now
  (level) => string, default Heading ${level}). History buttons now reflect
  undo/redo availability and disable while there is nothing to undo/redo.