Improve load behavior

[chuckdries]

• renders an empty box immediately, so hopefully it's less jarring when the content loads
• fetches the colors and emojis in parallel (instead of waiting for emojis to finish before requesting colors)

This will be a merge conflict with my other PR. I originally made all these changes together as they're both changes that I wanted for myself, but I split them apart for PRs. I'll handle rebasing whichever goes in second if you want both of them.

Thanks for this thing by the way, it's really neat and I was just about to have to build something similar for myself :)

[tarptaeya]

Instead of showing just border, I think that adding Loading user:repo text will give a feedback that the content is being loaded. Also pease create another pr for fetching emojis and colors in parallel (one pr per feature).