Deal with broken links

Fix broken links.

A paragraph involving a Juju link needed to be reworded
due to the destination page being removed from circulation.
A link may be put back if, and when, this gets resolved.
The subject concerns Juju application groups.

Change-Id: I303ebd262e31a501181727e9c69e04834c3c4d8d

doc/source/admin/managing-power-events-topology.rst

@@ -24,9 +24,9 @@ machines **3**, **11**, and **12**, each of which are not hyperconverged.
 
 .. note::
 
-    Juju applications can be given custom names at deploy time (see
-    `Application groups`_ in the Juju documentation). This document will call
-    out these `named applications` wherever they occur.
+   A Juju application can be given a custom name (i.e. named application) at
+   deploy time. When multiple units are involved this is referred to as an
+   application group.
 
 **machine 17**
 
@@ -330,5 +330,4 @@ along with their HA status and machine type:
 - ``rabbitmq-server`` (natively HA; metal)
 
 .. LINKS
-.. _Application groups: https://discourse.charmhub.io/t/application-groups
 .. _Landscape project: https://landscape.canonical.com

doc/source/admin/security/keystone.rst

@@ -75,7 +75,8 @@ see this `Fernet FAQ`_.
 .. important::
 
    Starting with OpenStack Rocky, only the Fernet format for authentication
-   tokens is supported. This is documented as a `known upgrade issue`_.
+   tokens is supported. This is documented on the
+   :doc:`cdg:upgrade-queens-to-rocky` page in the Deploy Guide.
 
 Fernet keys
 -----------
@@ -202,4 +203,3 @@ therefore advised.
 .. LINKS
 .. _Security compliance and PCI-DSS: https://docs.openstack.org/keystone/latest/admin/configuration.html#security-compliance-and-pci-dss
 .. _Fernet FAQ: https://docs.openstack.org/keystone/pike/admin/identity-fernet-token-faq.html
-.. _known upgrade issue: upgrade-issues.html#keystone-and-fernet-tokens-upgrading-from-queens-to-rocky

doc/source/admin/storage/swift.rst

@@ -288,8 +288,8 @@ Deployment
 
 .. warning::
 
-   Throughout this guide make sure ``openstack-origin`` matches the value you
-   used when `deploying OpenStack`_.
+   Throughout this guide make sure ``openstack-origin`` matches the OpenStack
+   release of the cloud.
 
 This example assumes there are two data centres, one in San Francisco (SF) and
 one in New York (NY). These contain Juju models 'swift-sf' and 'swift-ny'
@@ -505,7 +505,6 @@ contains the Juju "offers" that ``swift-sf.yaml`` will consume:
    juju deploy -m swift-sf ./swift-sf.yaml --overlay ./swift-sf-consumer.yaml
 
 .. LINKS
-.. _deploying OpenStack: install-openstack
 .. _Global clusters: https://docs.openstack.org/swift/latest/overview_global_cluster.html
 .. _Cross model relations: https://juju.is/docs/olm/cross-model-relations
 .. _swift-proxy: https://jaas.ai/swift-proxy