api-ref: document filter parameters when listing containers

[hongbin]

Currently, the server side supports the following filters [1]:

          container_allowed_filters = ['name', 'image', 'project_id', 'user_id',
                                     'memory', 'host', 'task_state', 'status',
                                     'auto_remove']

We'd better to document these parameters in our API reference: https://github.com/openstack/zun/blob/master/api-ref/source/containers.inc#list-all-containers

[1] https://github.com/openstack/zun/blob/master/zun/api/controllers/v1/containers.py#L207

Related-Bug:
https://bugs.launchpad.net/zun/+bug/1757152
https://bugs.launchpad.net/zun/+bug/1750208

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/582582

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/582582
Committed: https://git.openstack.org/cgit/openstack/zun/commit/?id=ba522edac7d8a6200fc3f78ad9dcc6ec2a0afde4
Submitter: Zuul
Branch: master

commit ba522edac7d8a6200fc3f78ad9dcc6ec2a0afde4
Author: Namrata <email address hidden>
Date: Fri Jul 13 19:27:35 2018 +0530

    Document filter parameters in API reference

    Document filter parameters when listing containers
    in API reference

    Closes-Bug: #1764003

    Change-Id: Ica68dab668b2544ed97f0c92750a80a907a0fb79

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/zun 2.0.0 release.