Textual-textarea is a text area (multi-line input) with syntax highlighting for
Textual.

It offers a full-featured text editor experience with VS-Code-like bindings, in
your Textual App:

  - Syntax highlighting and support for Pygments themes.
  - Move cursor and scroll with mouse or keys (including ctrl+arrow, PgUp/Dn,
    ctrl+Home/End).
  - Open (ctrl+o) and save (ctrl+s) files.
  - Cut (ctrl+x), copy (ctrl+c), paste (ctrl+u/v), optionally using the system
    clipboard.
  - Comment selections with ctrl+/.
  - Indent and dedent (optionally for a multiline selection) to tab stops with
    Tab and shift+Tab.
  - Automatic completions of quotes and brackets.
  - Select text by double-, triple-, or quadruple-clicking.
  - Quit with ctrl+q.