Right now the Zoom effect's "zoom in" action is bound by Meta+Equals,
which makes sense for ANSI US keyboards without numberpads which make
you hit the Shift key before you can get a plus sign, and pressing it
without Shift gets you an Equals sign.

But some ANSI US keyboards have a numberpad with a Plus key, and many
other keyboards without numberpads also have a Plus key, so we should
allow users of those keyboards to trigger "zoom in" as easily as users
of ANSI US keyboards.