Add basic slash command example

Co-authored-by: Danny <Rapptz@users.noreply.github.com>

examples/app_commands/basic.py

@@ -0,0 +1,71 @@
+from typing import Optional
+
+import discord
+from discord import app_commands
+
+MY_GUILD = discord.Object(id=0)  # replace with your guild id
+
+
+class MyClient(discord.Client):
+    def __init__(self, *, intents: discord.Intents, application_id: int):
+        super().__init__(intents=intents, application_id=application_id)
+        # A CommandTree is a special type that holds all the application command
+        # state required to make it work. This is a separate class because it
+        # allows all the extra state to be opt-in.
+        # Whenever you want to work with application commands, your tree is used
+        # to store it and work with it.
+        # Note: When using commands.Bot instead of discord.Client, the bot will
+        # maintain its own tree instead.
+        self.tree = app_commands.CommandTree(self)
+
+    # In this basic example, we just synchronize the app commands to one guild.
+    # Instead of specifying a guild to every command, we copy over our global commands instead.
+    # By doing so we don't have to wait up to an hour until they are shown to the end-user.
+    async def setup_hook(self):
+        # This copies the global commands over to your guild.
+        self.tree.copy_global_to(guild=MY_GUILD)
+        await self.tree.sync(guild=MY_GUILD)
+
+
+intents = discord.Intents.default()
+
+# In order to use a basic synchronization of the app commands in the setup_hook,
+# you have replace the 0 with your bots application_id you find in the developer portal.
+client = MyClient(intents=intents, application_id=0)
+
+
+@client.event
+async def on_ready():
+    print(f'Logged in as {client.user} (ID: {client.user.id})')
+    print('------')
+
+
+@client.tree.command()
+async def hello(interaction: discord.Interaction):
+    """Says hello!"""
+    await interaction.response.send_message(f'Hi, {interaction.user.mention}')
+
+
+@client.tree.command()
+@app_commands.describe(
+    first_value='The first value you want to add something to',
+    second_value='The value you want to add to the first value',
+)
+async def add(interaction: discord.Interaction, first_value: int, second_value: int):
+    """Adds two numbers together."""
+    await interaction.response.send_message(f'{first_value} + {second_value} = {first_value + second_value}')
+
+
+# To make an argument optional, you can either give it a supported default argument
+# or you can mark it as Optional from the typing library. This example does both.
+@client.tree.command()
+@app_commands.describe(member='The member you want to get the joined date from, defaults to the user who uses the command')
+async def joined(interaction: discord.Interaction, member: Optional[discord.Member] = None):
+    """Says when a member joined."""
+    # If no member is explicitly provided then we use the command user here
+    member = member or interaction.user
+
+    await interaction.response.send_message(f'{member} joined in {member.joined_at}')
+
+
+client.run('token')