feat(node): Add Portwork to onprem storage (#782)

* Add Portworx to onprem storage.

* Remove website/static/img/resources/resources/

diagrams/onprem/storage.py

@@ -20,6 +20,10 @@ class Glusterfs(_Storage):
     _icon = "glusterfs.png"
 
 
+class Portworx(_Storage):
+    _icon = "portworx.png"
+
+
 # Aliases
 
 CEPH = Ceph

docs/nodes/onprem.md

@@ -530,6 +530,9 @@ Node classes list of onprem provider.
 <img width="30" src="/img/resources/onprem/storage/glusterfs.png" alt="Glusterfs" style="float: left; padding-right: 5px;" >
 **diagrams.onprem.storage.Glusterfs**
 
+<img width="30" src="/img/resources/onprem/storage/portworx.png" alt="Portworx" style="float: left; padding-right: 5px;" >
+**diagrams.onprem.storage.Portworx**
+
 ## onprem.tracing