[Bug-gsl] Chebyshev Approx bug

[J Gray]

Hi there,

On the HTML manual, under Chebyshev Definitions, it says "...series is
computed using the following convention, which is needed ...". Having
checked the PDF version, it seems the equation describing the convention is
missing from the web version only. (Checked in chrome and chromium).

That missing half took a while to find!

Thanks very much,

Johnnie