Bare minimum place to start: See if you can get the team to agree that these documents should exist in every project root folder:
- README.md - What is this even for? Audience: Managers.
- CONTRIBUTING.md - What steps are needed to build this? What steps are needed to be able to run the tests? Audience: Developers.
- CHANGELOG.txt - Describes the contents of every tagged release. Audience: end users.
Stretch goal: pick a spot (readme is fine) and make a list of sources (data in) and sinks (data out). Include contact information for whoever can reset the credentials or fix the firewall.