completed documentation

README.md

 ## Description
 
-This role installs, enables and configures the PHP module `<module>`.
+This role installs, enables and configures the PHP module `filter`.
 
 ## Requirements
 
 ### Variables
 
+* php_mod_filter_default
+  * description:
+    * This option specifies the name of the filter you like to use by default.
+  * default: "unsafe_raw"
+
+* php_mod_filter_default_flags
+  * description:
+    * This option specifies the default flags to apply when the default filter is set.
+  * default: 0
+
 ## Processes
 
 None