[docs] [issue16813] use paths relative to CPython root in documentation building instructions

Sandro Tosi added the comment:

Out of curiosity, does anyone know if the following works on all or most systems?

$ open _build/html/index.html

it doesn't work on my Debian system: $ open _build/html/index.html Couldn't get a file descriptor referring to the console as open is a link to "openvt - start a program on a new virtual terminal (VT)." ---------- nosy: +sandro.tosi _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue16813> _______________________________________