Add cinder section to the configuration guide (#397)

Signed-off-by: Christian Berendt <[email protected]>

docs/guides/configuration-guide/openstack/cinder.md

@@ -0,0 +1,14 @@
+---
+sidebar_label: Cinder
+---
+
+# Cinder
+
+* [Cinder admin guide](https://docs.openstack.org/cinder/latest/admin/index.html)
+* [Cinder configuration guide](https://docs.openstack.org/cinder/latest/configuration/index.html)
+
+## Pure Storage FlashArray
+
+* https://support.purestorage.com/Solutions/OpenStack/OpenStack_Reference/Pure_Storage_FlashArray_Volume_Driver_for_OpenStack_Release_Notes
+* https://github.com/openstack/cinder/blob/master/cinder/volume/drivers/pure.py
+* https://docs.openstack.org/cinder/latest/configuration/block-storage/drivers/pure-storage-driver.html