feat: Ch03 Cross Correlation

Change-Id: I8b76318980e27e65f9b5b889b4173a5c498cb50f
diff --git a/dcs/frames/__init__.py b/dcs/frames/__init__.py
index 3e1318c..2284b9a 100644
--- a/dcs/frames/__init__.py
+++ b/dcs/frames/__init__.py
@@ -10,6 +10,7 @@
 from .ch02_phasor import Ch02PhasorWindow
 from .ch02_fourier import Ch02FourierWindow
 from .ch03_ergodic import Ch03ErgodicWindow
+from .ch03_cross import Ch03CrossCorrelationWindow
 
 
 def get_windows() -> List[Type[base.Window]]:
@@ -17,6 +18,7 @@
         Ch02PhasorWindow,
         Ch02FourierWindow,
         Ch03ErgodicWindow,
+        Ch03CrossCorrelationWindow,
     ]