[doc] Document pre/post/upgrade/batch ordered and concurrent steps in the tht deployment steps guide

[Bogdan Dobrelya]

The guide https://github.com/openstack/tripleo-heat-templates/blob/master/puppet/services/README.rst#deployment-steps looks missing details for the pre/post steps.

There is also a mention of the ansible tasks "Similar to the step_config, we allow a series of steps for the per-service upgrade sequence, defined as ansible tasks with a tag e.g "step1" for the first step, "step2" for the second". This would be nice to have some example links to repos or code snippets.

Ideally, all steps, including upgrade/containers variations, should be presented in dev docs as UML. It's a burden to keep them updated with ongoing changes. But even having those obsoleted *and* depicted, would make the learning curve less steep.

Perfectly, those UMLs must be autogenerated with tools like heat stack-preview / tox -e templates and the like. Otherwise, it is likely not doable to follow multiple dev changes done into deployment graphs manually.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/456175

[OpenStack Infra (hudson-openstack)]

Change abandoned by Bogdan Dobrelya (<email address hidden>) on branch: master
Review: https://review.openstack.org/456175

[Emilien Macchi (emilienm)]

This is an automated cleanup. This bug report has been closed because it
is older than 18 months and there is no open code change to fix this.
After this time it is unlikely that the circumstances which lead to
the observed issue can be reproduced.

If you can reproduce the bug, please:
* reopen the bug report (set to status "New")
* AND add the detailed steps to reproduce the issue (if applicable)
* AND leave a comment "CONFIRMED FOR: <RELEASE_NAME>"
  Only still supported release names are valid (FUTURE, PIKE, QUEENS, ROCKY, STEIN).
  Valid example: CONFIRMED FOR: FUTURE