Update release notes

Signed-off-by: cwasicki <[email protected]>

Author: cwasicki

RELEASE_NOTES.md

@@ -6,6 +6,12 @@
 
 ## Upgrading
 
+* Install command line tool as `reporting-cli`: The command line tool from the example is moved
+  to the package and can be called via `reporting-cli` or `python -m frequenz.client.reporting`
+  from the command line.
+* The command-line argument `--display` is renamed to `--format` for `reporting-cli`.
+* The `reporting-cli` tool can output CSV format, dataframe output is removed.
+
 ## New Features
 
 ## Bug Fixes