Add documentation for the discord module

src/discord/images.rs

@@ -1,5 +1,16 @@
+//! Utilities for handling Discord's image hashes.
+
 use twilight_model::util::ImageHash;
 
+/// Returns the URL of a user's avatar.
+///
+/// Arguments:
+/// * `hash` - The user's avatar hash (if available).
+/// * `user_id` - The user's ID.
+/// * `discriminator` - The user's discriminator.
+///
+/// Returns:
+/// [`String`] - The URL of the user's avatar.
 pub fn get_avatar_url(hash: Option<ImageHash>, user_id: u64, discriminator: u64) -> String {
     if let Some(hash) = hash {
         format!("https://cdn.discordapp.com/avatars/{user_id}/{hash}.webp?size=256")

src/discord/mod.rs

@@ -1,2 +1,7 @@
+//! A set of utilities to interact with Discord not included in the main framework.
+//! 
+//! It currently includes a markdown escaper and a utility to get image URLs from Discord's image
+//! hashes.
+
 pub mod images;
 pub mod sanitizing;