fix: allow interacting with embedded youtube player & enable keyboard shortcuts (backspace and 'k' to play/pause)

[micalevisk]

not sure if this is intentional but the current behavior doesn't allow us (at least on Firefox) to share the video or even open it on youtube, see:

before.webm

now we can:

now.webm

that's the same behavior as in https://plyr.io/#youtube but I don't know how they did in there

[kamilmysliwiec]

lgtm