Added a slash command for explaining link trackers

Lazy implementation, just copy pasted code. Perhaps one day I'll make it automated (so that it replies to any message containing "si=". For now you can just use `/trackers`

src/commands/oftenAsked/trackers.ts

@@ -0,0 +1,17 @@
+import { create_command } from '../../command';
+
+const message = `The **si=** is the tracking part of the URL and if you remove it it tracks less people.
+
+With **si=** it makes it roughly the same length as a **youtube.com** URL *(and the whole point of youtu.be is to be __shorter__)*`;
+
+export const command = create_command(
+    async () => message,
+    'Explains how and why to remove youtube tracking (so Greenfoot doesnt have to)',
+    ['url', 'youtube'],
+    undefined,
+    undefined,
+    {
+        config: (x) => x.toJSON(),
+        func: async () => ({ ephemeral: false, content: message }),
+    },
+);