Tutorials
Build good docs for basically nothing
Your customers need good documentation. Getting it online shouldn't depend on a software subscription or a spare engineering team.
Build a docs site with Docusaurus, add search and a glossary, and publish an API reference with Speccy. The series draws on my experience building documentation at Weavr and, before that, Codat.
Each tutorial adds to the same example. Start with an empty folder, or download the working site and take the pieces you need.