Add change note

Author: lcartey

change_notes/2024-09-11-rule-12-2-improvements.md

@@ -0,0 +1,6 @@
+- `RULE-12-2` - `RightHandOperandOfAShiftRange.ql`:
+  - Reduce false positives related to ranges determined by `%=`.
+  - Reduce false positives for integer constants with explicit size suffix were incorrectly identified as smaller types.
+  - Improve explanation of results, providing additional information on types and size ranges.
+  - Combine results stemming from the expansion of a macro, where the result is not dependent on the context.
+