Update README.md to suggest 0.2

Author: leggetter

README.md

@@ -16,7 +16,7 @@ terraform {
   required_providers {
     hookdeck = {
       source  = "hookdeck/hookdeck"
-      version = "~> 0.1"
+      version = "~> 0.2"
     }
   }
 }