Update generic component docs

Author: njooma

src/viam/components/generic/generic.py

@@ -19,7 +19,13 @@ class Generic(ComponentBase):
 
         class ComplexComponent(Generic):
 
-            async def do_command(self, command: Dict[str, Any]) -> Dict[str, Any]:
+            async def do_command(
+                self,
+                command: Mapping[str, ValueTypes],
+                *,
+                timeout: Optional[float] = None,
+                **kwargs
+            ) -> Mapping[str, ValueTypes]:
                 result = {key: False for key in command.keys()}
                 for (name, args) in command.items():
                     if name == 'on':