Add links to reply embeds and fix nitro custom server avatars not displaying

src/discord/images.rs

@@ -8,15 +8,21 @@ use twilight_model::util::ImageHash;
 /// * `hash` - The user's avatar hash (if available).
 /// * `user_id` - The user's ID.
 /// * `discriminator` - The user's discriminator.
+/// * `guild_id` - The guild ID, **only set if the user has Nitro and a custom avatar for the
+///   server. Otherwise, even in a server, this is NOT SET**.
 ///
 /// Returns:
 /// [`String`] - The URL of the user's avatar.
-pub fn get_avatar_url(hash: Option<ImageHash>, user_id: u64, discriminator: u64) -> String {
+pub fn get_avatar_url(hash: Option<ImageHash>, user_id: u64, discriminator: u64, guild_id: Option<u64>) -> String {
     if let Some(hash) = hash {
-        format!("https://cdn.discordapp.com/avatars/{user_id}/{hash}.png?size=256")
+        if let Some(guild_id) = guild_id {
+            return format!("https://cdn.discordapp.com/guilds/{guild_id}/users/{user_id}/avatars/{hash}.webp?size=256");
+        }
+
+        format!("https://cdn.discordapp.com/avatars/{user_id}/{hash}.webp?size=256")
     } else {
         format!(
-            "https://cdn.discordapp.com/embed/avatars/{}.png?size=256",
+            "https://cdn.discordapp.com/embed/avatars/{}.webp?size=256",
             match discriminator.to_string().as_str() {
                 "0" => (user_id >> 22) % 6,
                 _ => discriminator % 6,