Adding couchbase in onprem/database (https://www.couchbase.com/) (#164)

diagrams/onprem/database.py

@@ -20,6 +20,10 @@ class Cockroachdb(_Database):
     _icon = "cockroachdb.png"
 
 
+class Couchbase(_Database):
+    _icon = "couchbase.png"
+
+
 class Couchdb(_Database):
     _icon = "couchdb.png"
 

docs/nodes/onprem.md

@@ -49,6 +49,7 @@ Node classes list of onprem provider.
 - **diagrams.onprem.database.Cassandra**
 - **diagrams.onprem.database.Clickhouse**, **ClickHouse** (alias)
 - **diagrams.onprem.database.Cockroachdb**, **CockroachDB** (alias)
+- **diagrams.onprem.database.Couchbase**
 - **diagrams.onprem.database.Couchdb**, **CouchDB** (alias)
 - **diagrams.onprem.database.Dgraph**
 - **diagrams.onprem.database.Hbase**, **HBase** (alias)