[latexrefman] Extra "[nargs]" in \renewcommand synopsis

[Karl Berry]

Hi Vladimir,

    On the webpage: 
    https://latexref.xyz/_005cnewcommand-_0026-_005crenewcommand.html
    the first two synopses of \renewcommand are duplicates of each other.

Oops. Thanks much for that report. As Vincent already noted, I removed
the spurious [nargs], and updated the web site.

I also took the opportunity to (hopefully) clarify the optional argument
description somewhat, since it always confuses me whenever I have to
think about them :).

    P.S. Thanks enormously for this reference. It has been a lifesaver.

Glad it's helping. Just wish we had more time to work on it (or more
volunteers :). There is so much remaining to be done ... --thanks again, karl.