Create initial update_username command.

cogs/commands/data_management.py

@@ -43,3 +43,33 @@ class DataManagement(commands.Cog, name="Table Management"):
             await interaction.response.send_message(
                 "You shouldn't be using this message.", ephemeral=True
             )
+
+    @nextcord.slash_command(description="Request a username update. Admins must approve.")
+    async def update_username(
+        self,
+        interaction: nextcord.Interaction,
+        old_username: str = nextcord.SlashOption(
+            description="Username currently stored in highscores.", required=True
+        ),
+        new_username: str = nextcord.SlashOption(
+            description="Username to update to.", required=True
+        ),
+    ):
+        """
+        _summary_
+
+        Args:
+            interaction (nextcord.Interaction): Interaction that invoked the command
+            old_username (str): Username to replace.
+            new_username (str): Username to replace old with.
+        """
+        guild = highscores_data.get_guild(interaction.guild_id)
+        verify_channel = interaction.guild.get_channel(guild.verification_channel)
+
+        embed: nextcord.Embed = nextcord.Embed(title="Username change request.")
+        embed.add_field(name="Old username", value=old_username)
+        embed.add_field(name="New username", value=new_username)
+        await verify_channel.send(
+            content=f"Username change request from <@{interaction.user.id}>", embed=embed
+        )
+        await interaction.send("Request sent to admins for verification.", ephemeral=True)