Update README w/ manual release flow for now

Author: cstamas

README.md

@@ -3,4 +3,18 @@
 The build uses Nisse for "complete CI friendly" setup. See contents of `build.properties`.
 
 This file is single place that contains the version of Maven to generate BOMs for, and 
-is also used in resulting artifact versions as well.
+is also used in resulting artifact versions as well.
+
+## Releasing
+
+Due use of Nisse and Bom Builder (both rewrite plugins), the release procedure is currently
+manual:
+* set versions in POM to `-SNAPSHOT`-less
+* `mvn deploy -P maveniverse-release -Dnjord.autoPublish` -> this stages project to Central Portal
+* if validation OK, on Portal start publishing
+* tag release
+* set versions in POM to `-02-SNAPSHOT` (increment counter)
+* push all w/ tags
+
+Currently work happens on branches:
+* maven-3.9.x is for Maven 3.9.x line