Update release notes

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

Author: shsms

RELEASE_NOTES.md

@@ -12,7 +12,7 @@
 
 ## New Features
 
-<!-- Here goes the main new features and examples or instructions on how to use them -->
+- Calls to `microgrid.*_pool` methods now accept an optional `incremental` parameter.  Power requests sent to `*_pool` instances that have the `incremental` flag set, will get resolved separately, and their target power will be added to the target power calculated from non-incremental actors, if any.
 
 ## Bug Fixes