* Organize sections logically according to each step in the bug
reporting process
* Explain how bugs can be reported in different venues
* Explain how to report bugs in qubes-issues (will replace
CONTRIBUTING.MD)
* Link to Contributing page
* Generally improve wording and formatting
* Distinguish security issues from bugs and add link to information
on reporting security issues
* Add link to Mailing Lists page in place of direct link to Google
Groups web interface
* Add common redirects