Re: Documenting define-generic-mode.

[Richard Stallman]

       Similar defining macros use unquoted symbols too.  To be backward
       compatible, quoting the symbol is still allowed.

    Then the original text is OK.  I just thought that it _had_ to be
    [un]quoted, as in most macros.

For simplicity and consistency, we should document it as using an
unquoted arg.  There is no need to document the compatibility feature
of accepting the arg with a quote.

(It seems to be documented this way already.)