Priority parameter for JavaScript plugins

[JammingBen]

WHAT Needs to be Documented?

https://github.com/owncloud/core/pull/39359 introduced a priority for registering JavaScript plugins. A higher priority means the plugin will be registered/unregistered before others. It's optional and defaults to 50. The priority can be passed as third argument to the register method like so: OC.Plugins.register('OCA.Files.NewFileMenu', myFileMenuPlugin, 10);.

WHERE Does This Need To Be Documented (Link)?

https://doc.owncloud.com/server/10.8/developer_manual/app/fundamentals/js.html

(Optional) What Type Of Content Change Is This?

• [x] New Content Addition
• [ ] Old Content Deprecation
• [ ] Existing Content Simplification
• [ ] Bug Fix to Existing Content

(Optional) Which Manual Does This Relate To?

• [ ] Admin Manual
• [x] Developer Manual
• [ ] User Manual
• [ ] Android
• [ ] iOS
• [ ] Branded Clients
• [ ] Desktop Client
• [ ] Other