Update README.md

Author: maxfleetdev

README.md

@@ -2,3 +2,8 @@
 Custom command executer for Unity versions 2019+
 
 Requires TextMeshPro Package (Free)
+
+## How to use in 3-steps
+- Assign 'Command' attribute to a function (public or private)
+- Use either the CommandManager OR register the command at Awake/Start to the CommandRegister class
+- Call ExecuteCommand in CommandRegister with the user's input