[Rd] redesign R.css for HTML help pages

[Yihui Xie]

Hi,

I feel the CSS definitions for the HTML help pages are not visually
appealing enough. I admit this is a very subjective matter, so I don't
have strong arguments for this wishlist, although I wrote my version
of R.css with some web design instructions in mind (e.g. use
browser-safe sans-serif fonts).

Anyway, here is what I've done:
https://github.com/yihui/configuration/raw/master/R.css

This CSS file is under file.path(R.home('doc'), 'html') after installation.

Regards,
Yihui
--
Yihui Xie <xieyihui at gmail.com>
Phone: 515-294-2465 Web: http://yihui.name
Department of Statistics, Iowa State University
2215 Snedecor Hall, Ames, IA