Rename module and add init file to conform to ruff.

off_cooldown_bot/cogs/commands/__init__.py

@@ -0,0 +1,12 @@
+"""Cog loader. Adds all command cogs to the bot."""
+
+from nextcord.ext import commands
+
+from cogs.commands.birthday import BirthdayCog
+
+
+# This function will be called when this extension is loaded.
+# It is necessary to add these functions to the bot.
+def setup(bot: commands.Bot) -> None:
+    """Add all command classes to bot."""
+    bot.add_cog(BirthdayCog())