Install OpenStack in charm-deployment-guide vault

- [x] This doc is inaccurate in this way: ______
On Page: https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/install-openstack.html

In the openstack maas juju deployment guide under "vault"
https://jaas.ai/vault links back to openstack documentation which is a dead link.
Link on jaas for vault charm is https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/app-vault.html which is dead. This section is misleading and needs to include ALL steps needed to complete the process and NOT link out to some other page (in this case the page linked to has bad information). Moreover the point of using juju is to automate rote install processes, this either needs to be re-worded to include all steps needed to complete this phase of the installation or the vault juju package needs to be revised to automate this step.

This bug tracker is for errors with the documentation, use the following as a template and remove or add fields as you see fit. Convert [ ] into [x] to check boxes:

- [ ] This is a doc addition request.
- [ ] I have a fix to the document that I can paste below including example: input and output.

If you have a troubleshooting or support issue, use the following resources:

 - The mailing list: https://lists.openstack.org
 - IRC: 'openstack' channel on Freenode

-----------------------------------
Release: 0.0.1.dev280 on 2021-01-29 13:11:47
SHA: 7baf5cd01e90e8e23402f4131904c16d6c7c5cba
Source: https://opendev.org/openstack/charm-deployment-guide/src/deploy-guide/source/install-openstack.rst
URL: https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/install-openstack.html