adding new extract command to extract selector or main content as markdown, updateing version as 0.5.0

tests/test_cli.py

@@ -54,3 +54,19 @@ def test_clients_exits_cleanly_when_registry_is_missing():
 
     assert result.exit_code == 1
     assert "No browser clients found" in result.output
+
+def test_extract_markdown_command():
+    with patch("browser_cli.commands.extract.send_command", return_value="# Title\n") as send_command:
+        result = CliRunner().invoke(main, ["extract", "markdown"])
+
+    assert result.exit_code == 0
+    assert result.output == "# Title\n"
+    send_command.assert_called_once_with("extract.markdown", {"selector": None})
+
+def test_extract_markdown_command_with_selector():
+    with patch("browser_cli.commands.extract.send_command", return_value="## Post\n") as send_command:
+        result = CliRunner().invoke(main, ["extract", "markdown", "--selector", "article"])
+
+    assert result.exit_code == 0
+    assert result.output == "## Post\n"
+    send_command.assert_called_once_with("extract.markdown", {"selector": "article"})