Update to WWW Docs for Contributing Doc Patches [wwwdocs]

[Ralf Wildenhues]

* Joseph S. Myers wrote on Sat, Sep 25, 2010 at 12:34:17AM CEST:
> (You shouldn't need a bootstrap; 
> once the gcc/ directory has been fully configured you should be able to 
> run "make info" etc. in that directory in your build directory without the 
> rest of the build being needed.  Maybe info-gcc and dvi-gcc should be 
> recommended at top level if they work, to avoid any problems with 
> recursing into other directories without a full build.)

This doesn't currently work.  I opened PR bootstrap/45796 for this.

Cheers,
Ralf