Update docstring

Author: jhossbach

pylsp_ruff/plugin.py

@@ -139,6 +139,20 @@ def pylsp_lint(workspace: Workspace, document: Document) -> List[Dict]:
 
 
 def create_diagnostic(check: RuffCheck, settings: PluginSettings) -> Diagnostic:
+    """
+    Create a LSP diagnostic based on the given RuffCheck object.
+
+    Parameters
+    ----------
+    check : RuffCheck
+        RuffCheck object to convert.
+    settings : PluginSettings
+        Current settings.
+
+    Returns
+    -------
+    Diagnostic
+    """
     # Adapt range to LSP specification (zero-based)
     range = Range(
         start=Position(