Mention "wip" (work in progress) in readme

Author: aservedio

README.md

@@ -1,6 +1,9 @@
 # base/php-apache
 
-base docker image for docker apache mod-php
+Base docker image for docker apache mod-php.
+
+This is a work in progress for now. Will get cleaned up over time.
+
 
 ## tag
 base/php-apache