Fix documentation

[Kristi Nikolla]

Before moving to the OpenStack infrastructure, we were hosting our documentation at readthedocs.io.

We are not big-tent, so we can't use docs.openstack.org/developer/mixmatch for building the docs, but must still rely on readthedocs.io.

Readthedocs.io needs to be reconfigured for mixmatch.readthedocs.io

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/399676
Committed: https://git.openstack.org/cgit/openstack/mixmatch/commit/?id=e3a948aa3cf6302967444670c8d1f87706a77c8a
Submitter: Jenkins
Branch: master

commit e3a948aa3cf6302967444670c8d1f87706a77c8a
Author: Kristi Nikolla <email address hidden>
Date: Fri Nov 18 11:26:03 2016 -0500

    Added documentation

    After migrating to the OpenStack infrastructure, the documentation
    was missing. This patch re-adds it.

    Closes-Bug: 1640285

    Change-Id: I8f6f138b32483264d9ed8cdcc855b33f026097b6

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/399690

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/399690
Committed: https://git.openstack.org/cgit/openstack/mixmatch/commit/?id=86901e1ac544cec0512179835c0b580ca93d7d05
Submitter: Jenkins
Branch: master

commit 86901e1ac544cec0512179835c0b580ca93d7d05
Author: Kristi Nikolla <email address hidden>
Date: Fri Nov 18 11:50:13 2016 -0500

    Update documentation link in readme

    Last patch added the documentation. Since OpenStack doesn't build
    our documentation, we have to rely on external services. This
    patch makes the link in README.rst point to the correct url. [1]

    1. https://mixmatch.readthedocs.io

    Change-Id: I91040d9dbefa13cfc7938484e2f9f8f338afda4b
    Related-Bug: 1640285