[racket] reader.html: documentation for complex number reading

At Fri, 29 Mar 2013 13:23:17 +0000, Tim Brown wrote:
> The reader's definition (above) explicitly states that E is only an
> exponent marker for bases 2, 8 and 10 -- would you not be changing the
> meaning of #x1E+2 from 1 E 2 to... er... whatever 16^2 is? Or does the
> lack of delimiters in #x1E+2 mean that it's just an erroneous string of
> characters?

It's erroneous, because `#x' must be followed by a number in base 16,
and 1E+2 isn't a number in base 16.

I'm not a big fan of the number syntax, but I don't think we should
change it.