Add pyrefly as alternative lsp for python

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

@@ -125,6 +125,11 @@ Some languages require additional installations or setup steps, as noted.
   we also support [Phpactor](https://github.com/phpactor/phpactor) (language `php_phpactor`), which requires PHP 8.1+;
   and the experimental [PHPantom](https://github.com/PHPantom-dev/phpantom_lsp) backend (language `php_phpantom`)
 * **Python**
+  (by default, uses [Pyright](https://github.com/microsoft/pyright) (language `python`);
+  alternatives: [ty](https://github.com/astral-sh/ty) (language `python_ty`),
+  [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)
 * **R**  
   (requires installation of the `languageserver` R package)
 * **Ruby**