Remove valueless api.rst in doc/source

We have a detailed api doc: api-ref

Change-Id: I0f0027b5b2a338667356209ae6114abf149d97e0

doc/source/api.rst

@@ -1,60 +0,0 @@
-=====================
-Instance API Overview
-=====================
-
-List, Searching, Creating, Updating, and Deleting of Instance resources are done
-through the `/instances` resource. There are also several sub-resources, which
-allow further actions to be performed on an Instance.
-
-Instances
----------
-
-List Instances::
-
-  GET /instances
-
-List Instances Detailed::
-
-  GET /instances/detail
-
-Show Instance Details::
-
-  GET /instances/{instance_ident}
-
-Create Instance::
-
-  POST /instances
-
-Update Instance::
-
-  PATCH /instances/{instance_ident}
-
-Delete Instance::
-
-  DELETE /instances/{instance_ident}
-
-
-Instance Management
--------------------
-
-Instances can be managed through several sub-resources
-
-Instance State Summary::
-
-  GET /instances/{instance_ident}/states
-
-Change Instance Power State(on, off, reboot)::
-
-  PUT /instances/{instance_ident}/states/power
-
-Change Instance Provision State(rebuild)::
-
-  PUT /instances/{instance_ident}/states/provision
-
-Get Console::
-
-  GET /instances/{instance_ident}/states/console
-
-Show Console Output::
-
-  GET /instances/{instance_ident}/states/consoleoutput