Fix typo in quick-start.md

s/The will/This will/

Author: mattysweeps

docs/book/src/quick-start.md

@@ -57,7 +57,7 @@ in that API group-version:
 kubebuilder create api --group webapp --version v1 --kind Guestbook
 ```
 
-The will create the files `api/v1/guestbook_types.go` and
+This will create the files `api/v1/guestbook_types.go` and
 `controller/guestbook_controller.go` for you to edit.
 
 **Optional:** Edit the API definition or the reconcilation business logic.