Still, I have to write code to document, and then I'm back to the same old situation.

Try writing the documentation first, then the code. Now, you're allowed to go back and change the documentation if you discover a better way of doing it while coding, but go change the doc as these cases are being discovered.

Then, you won't have the documentation hanging over you at the "end" of a project.

Better yet, stop thinking about projects having an "end". Most programs are changed over time. There are just relatively active periods of development followed by relatively inactive periods of development.

Note that the above is all speculative on my part as I, myself, usually put off documentation until after I'm "done" with coding. This is all just do what I say, not as I do... Better to be a hypocrite who proclaims the truth rather than a silent person who has nothing good to say, I guess. Maybe someday, I'll actually catch myself following my own good advice. :-)