Add twitter embed fixer

When a new twitter.com/x.com link is seen, Valkyrie auto-replies with
the same link switched to fxtwitter.com (see
https://github.com/FixTweet/FxTwitter for the implementation). This
produces an actual Discord embed, as well as auto-expanding t.co links
and doing a couple of other useful things.

Those who wish to can also change the link to always redirect to nitter
instead of twitter (e.g. if you do not stay logged in or if twitter is
broken for you).

discord-scripts/fix-twitter-embed.ts

@@ -0,0 +1,57 @@
+import { PartialMessage, Client, Message, EmbedBuilder } from "discord.js"
+
+async function workingTwitterEmbeds(
+  message: Message<boolean> | PartialMessage,
+) {
+  if (message.author === null || message.author === undefined) {
+    return
+  }
+
+  if (!message.author.bot) {
+    const content = message.content ?? ""
+    if (content.match(/(https:\/\/(x|twitter).com\/[a-zA-Z0-9%/+]+)/)) {
+      const allLinks = Array.from(
+        content.matchAll(/(https:\/\/(x|twitter).com\/[a-zA-Z0-9%/+]+)/g),
+      )
+        .map(([twitterLink]) =>
+          twitterLink.replace(/https:\/\/(x|twitter)/, "https://fxtwitter"),
+        )
+        .join(" , ")
+
+      await message.channel.send(allLinks)
+    }
+
+    const receivedEmbeds = message.embeds
+    if (
+      !receivedEmbeds ||
+      !receivedEmbeds.find(
+        (embed) => embed.url && embed.url.includes("github.com"),
+      )
+    ) {
+      return
+    }
+
+    await message.suppressEmbeds(true)
+    const description = receivedEmbeds
+      .map((embed, i) => `(${i + 1}) [${embed.title}](${embed.url})`)
+      .join("\n")
+    const embed = new EmbedBuilder()
+      .setColor("#0099ff")
+      .setDescription(description)
+
+    message.channel.send({ embeds: [embed] })
+  }
+}
+
+// Follows up any message with 1+ Twitter links (including x.com) with a
+// message that includes fxtwitter links, which correctly embed into Discord,
+// expand t.co links, and have a couple of other nice features.
+export default function fixTwitterEmbeds(discordClient: Client) {
+  discordClient.on("messageCreate", (message) => {
+    workingTwitterEmbeds(message)
+  })
+
+  discordClient.on("messageUpdate", (_, newMessage) => {
+    workingTwitterEmbeds(newMessage)
+  })
+}