bug#25557: Documentation of format doesn't describe "g" accurately

[Eli Zaretskii]

> Cc: 25557@debbugs.gnu.org
> From: Clément Pit--Claudel <clement.pitclaudel@live.com>
> Date: Sat, 28 Jan 2017 11:18:44 -0500
> 
> I'm trying to get the shortest representation of a decimal number, rounded to 
> .01, not using scientific/exponential notation.  I'm using values computed in 
> ELisp to produce CSS style sheets, which until recently didn't allow for 
> exponential notation.  I'd like these stylesheets to be readable, so 100% is 
> better 100.00%, and 3.35em is better than 3.35004em. If my code is fed a 
> value of 5000px, I don't want it converted to 5e+3px, because many browsers 
> don't know how to parse that.

Then I think you want to use %d for integral values and %.2f for the
rest.