Update video modal to work with sites other than YouTube

[stevejalim]

@stevejalim commented on Wed Oct 30 2019

While most of our videos will be hosted on YouTube, it's possible that some will be embedded from (say) Vimeo.

However, the code for the modal implies that it's only expecting YouTube as a host, so this needs to be expanded to at least include Vimeo

[stevejalim]

@atopal @valgrimm Do either of you think this is a p1 (alpha) blocker, or can it be a p2?

[atopal]

yeah, until we have defined what P2 means. General backlog really.