There are a few problems with the proposed patch (v2).  I commented on those in Rietveld.  But, beyond that, I'm not convinced that the generated help.txt is an improvement over the original help.txt.  While it is formatted more consistently (a good thing), it is significantly longer (547 lines vs 369).  Some info is lost in the translation, for one, the menu div bars (---).  Some of the markup looks odd to me as plain text, for example:

    Upon startup with the ``-s`` option, IDLE will execute the file
    referenced by the environment variables ``IDLESTARTUP`` or
    ``PYTHONSTARTUP``. IDLE first checks for ``IDLESTARTUP``; if
    ``IDLESTARTUP`` is present the file referenced is run.  If 
    ``IDLESTARTUP`` is not present, IDLE checks for ``PYTHONSTARTUP``.

Also, I noticed that the deprecation notice, about running without a subprocess, near the end of the help text seems to be missing from the .rst.