Better document required permissions and Webhook implementation options

The current documentation around Webhook Management for Bitbucket Server and help messages do not give enough information to the end user about:

• What plugin (and plugin version) is required for the Plugin implementation ? (I believe this is https://marketplace.atlassian.com/apps/1215474/post-webhooks-for-bitbucket?tab=overview&hosting=datacenter)
• What permissions are required for the credentials provided (Admin permissions)