Update release notes

Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

RELEASE_NOTES.md

@@ -10,7 +10,7 @@
 
 ## New Features
 
-<!-- Here goes the main new features and examples or instructions on how to use them -->
+- The `MovingWindow` now has an async `wait_for_samples` method that waits for a given number of samples to become available in the moving window and then returns.
 
 ## Bug Fixes