It's time to get our wonderful emojis merged to branding.

Before we do that, we need to sort out some legal stuff on this branch. Here's what needs to be done:

• We have remixed Twemoji's to make these, so we need to include attribution and explain which changes have been made. These are licensed under CC BY 4.0. Let's add these to the README.
• Another provision in this license is that we cannot impose additional restrictions, which sadly, our current license does (no commercial use). The solution there is that the lemojis can just be licensed under CC BY 4.0, and the rest of the repo can use our current license. We need to add the license itself to the lemoji folder, and then add information about this into our README, probably in the same place where we're putting attribution.

After this is done, we should be good to merge.