Make reference to service-types-authority from plugins.rst
We want people creating plugins (that add services) to be aware of the
service-types-authority (STA), so this change adds a Prerequisites
section and notes the existince of the STA there, and the need to apply
there to create a service-type.
Change-Id: I1aa48fe231aaa4499f8b4fe336abea668841b9af
diff --git a/doc/source/plugins.rst b/doc/source/plugins.rst
index 5b3c6cf..fae1a1d 100644
--- a/doc/source/plugins.rst
+++ b/doc/source/plugins.rst
@@ -12,6 +12,15 @@
be sure that they will continue to work in the future as DevStack
evolves.
+Prerequisites
+=============
+
+If you are planning to create a plugin that is going to host a service in the
+service catalog (that is, your plugin will use the command
+``get_or_create_service``) please make sure that you apply to the `service
+types authority`_ to reserve a valid service-type. This will help to make sure
+that all deployments of your service use the same service-type.
+
Plugin Interface
================
@@ -250,3 +259,5 @@
For additional inspiration on devstack plugins you can check out the
`Plugin Registry <plugin-registry.html>`_.
+
+.. _service types authority: https://specs.openstack.org/openstack/service-types-authority/