add /pub link command and appropriate config entry

example-config.toml

@@ -14,4 +14,5 @@ emoji_reacts = "🚂😠🚇"
 weekday = 3  # Thursday
 hour = 20
 channel_id = 1234567890
-description = "Casual chat and food. All welcome."
+description = "Casual chat and food. All welcome."
+web_url = "https://example.com/"

kmibot/config.py

@@ -22,7 +22,7 @@ class PubConfig(BaseModel):
     weekday: int
     hour: int
     minute: int = 0
-
+    web_url: str
 
 class FerryConfig(BaseModel):
     api_url: str

kmibot/modules/pub/commands.py

@@ -365,7 +365,18 @@ async def help(self, interaction: discord.Interaction) -> None:  # noqa: A003
                     "/pub table <table_no> - add the table number and let others know",
                     "/pub attendees - get the people coming to the next pub, including AutoPub attendees",
                     "/pub change - move the location of the pub and ping all attendees.",
+                    "/pub link - get a link to the website"
                 ],
             ),
             ephemeral=True,
         )
+
+    @command(description="Get a link to the web service") # type: ignore[arg-type]
+    async def link(self, interaction: discord.Interaction) -> None: #noqa: A003
+        LOGGER.info(f"{interaction.user} used /pub link")
+        assert interaction.guild is not None
+
+        await interaction.response.send_message(
+                "Here you go:\n"+self.config.pub.web_url,
+                epheremal=True
+        )