Link Previews And Improvements

Hai! now adds link previews when provided by the Mastodon API.

For most embeds, you can view them alongside attached images. For other links, they’ll be displayed under the content as a blockquote.

Also some improvements:

• Expanded areas where –accent-color is used, and added –accent-text. If you style these both, you don’t have to worry about contrast issues anymore.
• Added screen reading labels to the buttons on the bottom of posts.
• Fixed instances of phantom play buttons appearing.
• Fixed squished emoji. Emoji will no longer be squished.
• Loading a new theme fades the old theme out and fades in the new one.