Adding a link to ubuntu-bug in the Quality contact page

[Alberto Salvia Novella]

Since many people trend to ask in this mailing list about bugs and 
support, perhaps we can make a warn in the Quality contact 
<https://wiki.ubuntu.com/QATeam/Contact> wiki-page about:

- Using the ubuntu-bug 
<https://help.ubuntu.com/community/ReportingBugs#Reporting_non-crash_hardware_and_desktop_application_bugs> 
reporting tool for bugs.
- Using the Ask Ubuntu <http://askubuntu.com/> support platform for 
assistance.

What do you think?