completed documentation

README.md

 ## Description
 
-This role installs, enables and configures the PHP module `<module>`.
+This role installs, enables and configures the PHP module `ffi`.
 
 ## Requirements
 
 ### Variables
 
+* php_mod_ffi_enable
+  * description:
+    * This option allows enabling or disabling  FFI API usage, or restricting it only to the CLI SAPI and preloaded files.
+  * choices: [false, true, preload]
+  * default: "preload"
+
+* php_mod_ffi_preload
+  * description:
+    * This option allows preloading of FFI bindings during startup.
+  * default: ""
+
 ## Processes
 
 None