Update README.md

Author: kitsunet

README.md

@@ -1,4 +1,4 @@
 Full Page Cache
 ===============
 
-WIP,does not invalidate entries ever. Do not use yet!
+Still WIP but cache invalidation should work just fine and this package should bring performance improvements without drawback (apart from having more caches to store) for many websites. Next steps would be proxy cache headers and better ways to influence the caching from within the request.