Docs: Add quota management (rackerlabs#591)

Adds docs for quota management.

docs/openstack-quota-managment.md

@@ -0,0 +1,57 @@
+# Quota Management
+
+Resouce quotas can be set in an OpenStack environment to ensure that we do not unintentionally exhaust
+the capacity. In OpenStack quotas can be set to give each resource some operational limit.
+
+Quotas are checked in the follwing order:
+
+* Project specific limit
+
+If set for a specific resource this limit will be used first. Exmaple, for a project we can set quotas
+for any resource like so:
+
+```shell
+  openstack quota set --cores 100 <project>
+```
+
+* Default limits
+
+These are hard limit set the database under `quota_classes` for the default quota class. If project sepcific
+limit is not set for a given resource and default limit is set, OpenStack uses this limit.
+
+To set a default limit for a resource:
+
+```shell
+  openstack quota set --cores 120 default
+```
+
+!!! note
+    Once the default limit is set via the API, it takes precedence over config limits. Once it is set, we can only
+    modify the limit, but it can not be deleted via the API. It can however be deleted manually from the database.
+
+
+* Config provided limits
+
+We can set limits on resource through the config file under the quota config group.
+
+
+### Useful quota commands
+
+```shell title="Show the default quota"
+  openstack quota show --default
+```
+
+```shell title="Show quota for a project"
+  openstack quota show <project>
+```
+
+```shell title="Update quota for resource instance in default class"
+  openstack quota set --instances 15 default
+```
+
+```shell title="Update quota for a resource for a project"
+  openstack quota set --instances 20 <project>
+```
+
+!!! note
+    Quotas class has been replaced with a new driver unified limits. Please see OpenStack docs for unified limits.

mkdocs.yml

@@ -263,6 +263,8 @@ nav:
               - Nova CPU Allocation Ratio: openstack-cpu-allocation-ratio.md
               - Nova PCI Passthrough: openstack-pci-passthrough.md
               - Host Aggregates: openstack-host-aggregates.md
+          - Quota Management:
+              - Quota Management: openstack-quota-managment.md
           - Images:
               - Glance Images Creation: openstack-glance-images.md
           - Identity: