Revise README

README.org

@@ -23,9 +23,12 @@ Highlights:
 of ~crdt.el~ not working.  Because currently the network protocol is
 not stablized, behavior when using mismatched versions is
 unexpectable.
-- Strictly speaking, it should works when =crdt-protocol-version= are defined and the same on all peers.
-  But why not save some hassle and keep everyone on the latest version.
-- To upgrade, just =M-x package-reinstall crdt=, then preferably restart Emacs.
+- Strictly speaking, it should works when =crdt-protocol-version= are
+  defined (added after version =0.2.5=) and the same on all peers.
+  But why not save some hassle and keep everyone on the latest
+  version.
+- To upgrade, just =M-x package-reinstall crdt=, then preferably
+  restart Emacs. To check your ~crdt.el~ version, =M-x crdt-version=.
 
 ** Start a shared session