feat: Ch03 Ergodic Processes

Change-Id: Ic73be4a8ed8afd2e7d181536fd9d420c75f0781f
diff --git a/dcs/frames/__init__.py b/dcs/frames/__init__.py
index f6aa703..3e1318c 100644
--- a/dcs/frames/__init__.py
+++ b/dcs/frames/__init__.py
@@ -9,12 +9,14 @@
 
 from .ch02_phasor import Ch02PhasorWindow
 from .ch02_fourier import Ch02FourierWindow
+from .ch03_ergodic import Ch03ErgodicWindow
 
 
 def get_windows() -> List[Type[base.Window]]:
     return [
         Ch02PhasorWindow,
         Ch02FourierWindow,
+        Ch03ErgodicWindow,
     ]