Migrate discord.py custom help command pin to site (#698)

Author: Diabolical5777

pydis_site/apps/content/resources/guides/python-guides/discordpy_help_command.md

@@ -0,0 +1,66 @@
+---
+title: Custom Help Command
+description: "Overwrite discord.py's help command to implement custom functionality"
+---
+
+First, a basic walkthrough can be found [here](https://gist.github.com/InterStella0/b78488fb28cadf279dfd3164b9f0cf96) by Stella#2000 on subclassing the HelpCommand. It will provide some foundational knowledge that is required before attempting a more customizable help command.
+
+## Custom Subclass of Help Command
+If the types of classes of the HelpCommand do not fit your needs, you can subclass HelpCommand and use the class mehods to customize the output. Below is a simple demonstration using the following methods that can also be found on the documenation:
+
+- [filter_commands](https://discordpy.readthedocs.io/en/stable/ext/commands/api.html#discord.ext.commands.HelpCommand.filter_commands)
+
+- [send_group_help](https://discordpy.readthedocs.io/en/stable/ext/commands/api.html#discord.ext.commands.HelpCommand.send_bot_help)
+
+- [send_command_help](https://discordpy.readthedocs.io/en/stable/ext/commands/api.html#discord.ext.commands.HelpCommand.send_command_help)
+
+- [send_group_help](https://discordpy.readthedocs.io/en/stable/ext/commands/api.html#discord.ext.commands.HelpCommand.send_group_help)
+
+- [send_error_message](https://discordpy.readthedocs.io/en/stable/ext/commands/api.html#discord.ext.commands.HelpCommand.send_error_message)
+
+```python
+class MyHelp(commands.HelpCommand):
+
+    async def send_bot_help(self, mapping):
+        """
+        This is triggered when !help is invoked.
+
+        This example demonstrates how to list the commands that the member invoking the help command can run.
+        """
+        filtered = await self.filter_commands(self.context.bot.commands, sort=True) # returns a list of command objects
+        names = [command.name for command in filtered] # iterating through the commands objects getting names
+        available_commands = "\n".join(names) # joining the list of names by a new line
+        embed  = disnake.Embed(description=available_commands)
+        await self.context.send(embed=embed)
+
+    async def send_command_help(self, command):
+        """This is triggered when !help <command> is invoked."""
+        await self.context.send("This is the help page for a command")
+
+    async def send_group_help(self, group):
+        """This is triggered when !help <group> is invoked."""
+        await self.context.send("This is the help page for a group command")
+
+    async def send_cog_help(self, cog):
+        """This is triggered when !help <cog> is invoked."""
+        await self.context.send("This is the help page for a cog")
+
+    async def send_error_message(self, error):
+        """If there is an error, send a embed containing the error."""
+        channel = self.get_destination() # this defaults to the command context channel
+        await channel.send(error)
+
+bot.help_command = MyHelp()
+```
+
+You can handle when a user does not pass a command name when invoking the help command and make a fancy and customized embed; here a page that describes the bot and shows a list of commands is generally used. However if a command is passed in, you can display detailed information of the command. Below are references from the documentation below that can be utilised:
+
+- [Get the command object](https://discordpy.readthedocs.io/en/latest/ext/commands/api.html#discord.ext.commands.Bot.get_command)
+
+- [Get the command name](https://discordpy.readthedocs.io/en/latest/ext/commands/api.html#discord.ext.commands.Command.name)
+
+- [Get the command aliases](https://discordpy.readthedocs.io/en/latest/ext/commands/api.html#discord.ext.commands.Command.aliases)
+
+- [Get the command brief](https://discordpy.readthedocs.io/en/latest/ext/commands/api.html#discord.ext.commands.Command.brief)
+
+- [Get the command usage](https://discordpy.readthedocs.io/en/latest/ext/commands/api.html#discord.ext.commands.Command.usage)