Resolve "Create outline and placeholders for dev/reseller package integration docs"

Documentation only. See #835 (closed) and parent epic

Closes #835 (closed)

docs/developer/package-integration/package-integration-database.md

+# Big Bang Package: Database Integration
+
+If the package you are integrating connects to a database or cache server, you will need to follow the instructions below to integrate this feature into Big Bang
+
+## Prerequisites
+
+TBD
+
+## Integration
+
+## Validation