Documented loop.depth and added loop.depth0.
diff --git a/CHANGES b/CHANGES
index d45f78c..7dac016 100644
--- a/CHANGES
+++ b/CHANGES
@@ -28,6 +28,8 @@
   of blocks.
 - Added `map`, `select`, `reject`, `selectattr` and `rejectattr`
   filters.
+- Added support for `loop.depth` to figure out how deep inside a recursive
+  loop the code is.
 
 Version 2.6
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