Update footer

Author: mcornella

_Footer.md

@@ -1,5 +1,7 @@
 [Homepage](https://github.com/ohmyzsh/ohmyzsh)
 — [Website](https://ohmyz.sh)
-— [Twitter](https://twitter.com/ohmyzsh)
-— [Merchandise](https://shop.planetargon.com/collections/oh-my-zsh?utm_source=github)
+— [Merchandise](https://commitgoods.com/collections/oh-my-zsh?utm_source=github)
 — [Discord](https://discord.gg/ohmyzsh)
+— [X (Twitter)](https://x.com/ohmyzsh)
+— [BlueSky](https://bsky.app/profile/ohmyz.sh)
+— [Mastodon](https://mstdn.social/@ohmyzsh)