fold 7.x README updates in

Author: nicholascar

README.md

@@ -43,7 +43,8 @@ Help with maintenance of all of the RDFLib family of packages is always welcome
 
 ## Versions & Releases
 
-* `main` branch in this repository is the unstable release
+* `main` branch in this repository is the current unstable release - version 8 alpha
+* `7.1.4` tidy-up release, possibly last 7.x release
 * `7.1.2` current stable release, small improvements on to 7.1.1
 * `7.1.1` previous stable release
     * see <https://github.com/RDFLib/rdflib/releases/tag/7.1.1>