The Elixir version is already specified earlier in this guide, so I wouldn't specify it again. Otherwise it's yet another place where to change the version when it changes in the future.
Embed.css and embed.js are copied from the original (pleroma) merge request.
Please don't just copy files, especially when they are licensed in a way the requires attribution. A better way…
That sounds reasonable enough to me. I don't have a strong opinion on these kinds of styling, even though I'd have probably ended up capitalizing them all myself
Well, to be clear; That's how…
I didn't realise the non-British was more prevalent. It indeed makes sense to use the non-British form then. I am opinionated about it, but I'm also just one person, so there's that :p