update README

Author: minghsu0107

README.md

@@ -1,5 +1,5 @@
 # Update Kustomization
-A Drone CI plugin for updating an image tag in using kustomize.
+A Drone CI plugin for updating an image tag using kustomize.
 
 Environment variables:
 - `SSH_KEY`: Base64-encoded private key of your manifest repo
@@ -26,4 +26,4 @@ Example usage in a Drone pipeline:
   when:
     event: push
 ```
-Where `staging/mysvc` is the kustomization folder path relative to the project root.
+Where `staging/mysvc` is the kustomization folder path relative to the project root.