feat: add QML language support via Qt's qmlls (#1635)

docs/01-about/020_programming-languages.md

@@ -130,6 +130,8 @@ Some languages require additional installations or setup steps, as noted.
   [pyrefly](https://github.com/facebook/pyrefly) (language `python_pyrefly`),
   [Jedi](https://github.com/palotas/jedi-language-server) (language `python_jedi`);
   ty and pyrefly require `uv`/`uvx` in PATH)
+* **QML**
+  (requires Qt 6, provides `qmlls` or `qmlls6` on PATH; see the [Qt qmlls documentation](https://doc.qt.io/qt-6/qtqml-tool-qmlls.html))
 * **R**  
   (requires installation of the `languageserver` R package)
 * **Ruby**