Update README.md

Author: benkeen

README.md

@@ -1,4 +1,12 @@
-module-system-check
-===================
+## module-system_check
 
-The System Check module. 
+This module replaces the older Database Integrity module. It offers a few simple, quick tests to run on your Form Tools installation: kind of like taking your car to get it serviced - except this is free!
+
+### Documentation
+
+[http://modules.formtools.org/system_check/](http://modules.formtools.org/system_check/)
+
+### Form Tools Extensions
+
+For further information about Form Tools extensions, check out the following link:
+[http://www.formtools.org/extensions.php](http://www.formtools.org/extensions.php)