docs(security:authorization): correct import (#158)

Fixing the imported AuthorizerResponse on allowing guest user in defining policies. I got TypeScript error when I don't import it as a type.

Author: rvyhvn

content/docs/security/authorization.md

@@ -315,7 +315,7 @@ export default class PostsController {
 import User from '#models/user'
 import Post from '#models/post'
 import { BasePolicy, allowGuest } from '@adonisjs/bouncer'
-import { AuthorizerResponse } from '@adonisjs/bouncer/types'
+import type { AuthorizerResponse } from '@adonisjs/bouncer/types'
 
 export default class PostPolicy extends BasePolicy {
   @allowGuest()