Correct a description and a link in www/hacking.html, as a follow-up to r19836.
Correct a description and a link in www/hacking.html, as a follow-up
to r19836.

Patch by: Kobayashi Noritada <nori1@dolphin.c.u-tokyo.ac.jp>

* www/hacking.html (docs): Delete a sentence for an old design
  specification in the DocBook XML version and link to the new HTML
  version.



git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@859914 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion