Add ravendb resource node

Signed-off-by: Jon Stelly <967068+jonstelly@users.noreply.github.com>

diagrams/onprem/database.py

@@ -76,6 +76,10 @@ class Postgresql(_Database):
     _icon = "postgresql.png"
 
 
+class Ravendb(_Database):
+    _icon = "ravendb.png"
+
+
 class Scylla(_Database):
     _icon = "scylla.png"
 

docs/nodes/onprem.md

@@ -96,6 +96,7 @@ Node classes list of onprem provider.
 - **diagrams.onprem.database.Neo4J**
 - **diagrams.onprem.database.Oracle**
 - **diagrams.onprem.database.Postgresql**, **PostgreSQL** (alias)
+- **diagrams.onprem.database.Ravendb**
 - **diagrams.onprem.database.Scylla**
 
 ## onprem.dns