Amend docstring for Grid.current property

Signed-off-by: Daniel Zullo <[email protected]>

Author: daniel-zullo-frequenz

src/frequenz/sdk/timeseries/grid.py

@@ -92,7 +92,7 @@ def power(self) -> FormulaEngine[Power]:
 
     @property
     def current(self) -> FormulaEngine3Phase[Current]:
-        """Fetch the grid power for the microgrid.
+        """Fetch the grid current for the microgrid.
 
         This formula produces values that are in the Passive Sign Convention (PSC).