New feature on firefox-dev.tools

[Patrick Brosset]

Thanks to Sébastien Blin (AmarOk1412 <https://github.com/AmarOk1412> on
github, :amarok
<https://bugzilla.mozilla.org/user_profile?login=amarok%40enconn.fr> on
bugzilla) for adding a really nice new feature
<https://github.com/captainbrosset/devtools-bug-finder/pull/28> to the
http://firefox-dev.tools website that lets you pass in query parameters to
initiate a search immediately when the page loads.

A few examples:
- all good-first-bugs: http://firefox-dev.tools/?easy
- all mentored bugs: http://firefox-dev.tools/?mentored
- all good-first mentored inspector bugs:
http://firefox-dev.tools/?easy&mentored&tool=inspector

This should be useful when new contributors ask which bugs they could work
on in a specific tool.

Thank you Sébastien!
Patrick