Update documentation for one API call in connection.py

src/rhsm/connection.py

@@ -1442,11 +1442,12 @@ def get_supported_resources(self) -> dict:
 
         return self.resources
 
-    def supports_resource(self, resource_name: str) -> bool:
-        """
-        Check if the server we're connecting too supports a particular
-        resource. For our use cases this is generally the plural form
-        of the resource.
+    def supports_resource(self, resource_name: Optional[str]) -> bool:
+        """Check if the server supports a particular resource.
+
+        :param resource_name:
+            Resource to be requested.
+            When `None`, API call 'GET /' is made to cache all supported resources.
         """
         if self.resources is None:
             self._load_supported_resources()