Zoom in/out entire page with ctrl +/-

[AncuL001]

Title hopefully describes everything.

This is a feature basically built in to every websites. Since changing font size is not trivial and i kinda miss Spotify's zoom in/out ability, i think it's a good accessibility feature to have

[SO9010]

We are trying to stay simple as possible to add not to many moving parts to ensure that program stays minimalistic maybe we should properly come up with an ethos what do you think @jacksongoode

Edit but this could be a setting here: #617