Automatically join threads, add placeholder code for pin context menu

cogs/context_menus/school_cm.py

@@ -0,0 +1,32 @@
+import discord
+from discord import ApplicationContext
+from discord.ext import commands
+from discord.commands import message_command
+
+from startup.didier import Didier
+
+
+class SchoolCM(commands.Cog):
+    def __init__(self, client: Didier):
+        self.client: Didier = client
+
+    @message_command(name="Pin")
+    async def _pin_cm(self, ctx: ApplicationContext, message: discord.Message):
+        # In case people abuse, check if they're blacklisted
+        blacklist = []
+
+        if ctx.user.id in blacklist:
+            return await ctx.respond(":angry:", ephemeral=True)
+
+        if message.is_system():
+            return await ctx.respond("Dus jij wil system messages pinnen?\nMag niet.", ephemeral=True)
+
+        await message.pin(reason=f"Didier Pin door {ctx.user.display_name}")
+        await ctx.respond("📌", ephemeral=True)
+
+
+def setup(client: Didier):
+    # client.add_cog(SchoolCM(client))
+    # TODO wait for bug to be fixed in lib then uncomment this
+    #   when used in dm, tries to create a DM with the bot?
+    pass