When we run puppeteer with Firefox,
the `--window-size` option does not work,
which makes the bottom part of
the page cut off.
This commit fixes this issue
by setting the screen default viewport
to the maximum size of the window.
Go to Recent Topics on "#", no hash and "#recent_topics".
Go to Recent Topics as the last destination for escape key.
Map `a` key to All messages and change its hash to
`#all_messages`.
Riken Shah
Anders Kaseorg
Aman Agrawal