Manager "readmes" or "user guides" are a bad trend. Managers: get the fuck over yourselves with this nonsense.
No, writing self-serving docs about "how to work with me" is not a good way to build trust, especially since I promise you that you have some glaring blind spot that will inevitably show up in your behavior vs doc and undermine your credibility
I'm sure many of you are earnestly trying to do right by your teams with this but really, I would advise against it. You're not a computer program, you're a human being. You contain multitudes.