A few years ago I left the company I was was working for. We had an internal doc wiki that hardly anyone used. I was one of the ones who did and I would document code changes and things like how to setup a dev environment and to list known gotchas. During my final week when I was doing code handover I sent an email around the company pointing out that the wiki would answer most of the questions they might have about…
But why are your instructions in the back closet when they could be taped directly to the code in the readme or in the comments and error messages? I've had similar phone calls, to which I respond "it's all in the README." Never heard from them again.
Few people took any notice of it.