I do this for all code I add devs to or hand off to. For instance, startup code I walk away from and hand over to contractors. A markdown doc with some high-level concepts + a hierarchical bulleted list explaining the module structure goes a long way.
it's amazing how uncommon this is in the big business world. Individuals have pride, cogs do not. I've been in both camps. Currently I'm a cog because it's better for my life at the moment. I'm frustrated by the lack of simple documentation - but at the end of the day I'm not really interested in fixing it.
