Note about how to properly set up composer namespaces for plugins.

Currently there are pretty wild plugin names out there - and some even violate the CakePHP namespace.
This should clear things up and provide clear conventions around it

FooBar username
Logging plugin

=> foo-bar/cakephp-logging

Just as done by

- https://github.com/josegonzalez/cakephp-csvview ("josegonzalez/cakephp-csvview")
- https://github.com/dereuromark/cakephp-tools ("dereuromark/cakephp-tools")
- https://github.com/cakephp/localized (CakePHP owned - "cakephp/localized")

**And violated by**

- https://github.com/jadb/cakephp-monolog - [ticket pending](https://github.com/jadb/cakephp-monolog/issues/11)