docs: Fix testing instructions for mongo
the make task name is start-mongodb_5
We might need to consolidate naming conventions for start- / dev- makefile tasks
@@ -168,7 +168,7 @@ tests:
- `make dev-mysql8`: MySQL 8
- `make dev-postgres`: PostgreSQL 10
- `make dev-sqlite`: SQLite
-- `make dev-mongodb5`: MongoDB 5
+- `make dev-mongodb_5`: MongoDB 5
\*_On windows:_
If not using WSL, `make` is not available and you should just see what your
