build/release.sh: add some comments

contrib/release.sh

@@ -1,9 +1,13 @@
+#!/bin/bash
+
+# Note: steps before doing a new release:
 #
-# Note: update locale before:
+# - update locale:
 #     1. cd /opt/electrum-locale && ./update && push
 #     2. cd to the submodule dir, and git pull
 #     3. cd .. && git push
-#!/bin/bash
+# - update RELEASE-NOTES and version.py
+# - git tag
 
 ELECTRUM_DIR=/opt/electrum
 WWW_DIR=/opt/electrum-web