Update README.md

README.md

@@ -1,4 +1,24 @@
 SortableGridField
 =================
 
-Adds drag and drop functionality to SilverStripe 3.0's GridField
+Adds drag and drop functionality to SilverStripe 3.0's GridField
+
+## Usage
+*mysite/_config.php*
+
+  :::php
+  GridFieldSortableObject::add_sortable_class('{ClassName}'); //For has_many relationships
+  
+  GridFieldSortableObject::add_sortable_many_many_relation('{Owner ClassName}', '{Component Name}'); //For many_many relationships
+  
+*Grid Field Config*
+  :::php
+  $myGridConfig->addComponent(new GridFieldSortableRows());
+  
+## Known Isuses
+* Many_many relationship is largely untested and may not work as expected
+* Documentation on GridFieldSortableObject is very poor
+
+
+## Credits
+GridFieldSortableObject is based off of dataobject_manager's SortableDataObject class by @unclecheese