Use layer norm to improve stability of the Q network

Change-Id: Ica9eb446e58c74cfcdb995ad5f79faa6e137f03e
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/frc971/control_loops/swerve/velocity_controller/model.py b/frc971/control_loops/swerve/velocity_controller/model.py
index 7d62b0e..acbac08 100644
--- a/frc971/control_loops/swerve/velocity_controller/model.py
+++ b/frc971/control_loops/swerve/velocity_controller/model.py
@@ -175,6 +175,8 @@
                 name=f'denselayer{i}',
                 features=hidden_size,
             )(x)
+            # Layernorm also improves stability.
+            x = nn.LayerNorm(name=f'layernorm{i}')(x)
             x = self.activation(x)
 
         x = nn.Dense(