v1.2.1

Fixes:

• Fix a few missing elements in the gif section.

Tweaks:

• Made starred message panes have dark background, the same background color as the chat area.

Additions:

• Styles for stickers, stickers picker menu, etc. Addresses #12.
• ::selection and ::-moz-selection should be styled properly. Closes #13.
• ::-webkit-input-placeholder selector should be styled now.

Deletions:

• Remove fallback @updateURL because it doesn't work the way I thought it works.