docs: clarified how -shortmuteset message works

shortmute/shortmute.py

@@ -311,7 +311,12 @@ class Shortmute(commands.Cog):
     @commands.guild_only()
     @commands.admin()
     async def shortmute_config_message(self, ctx: commands.Context, enabled: bool = None):
-        """Manages if /shortmute Direct Messages its target."""
+        """Manages if /shortmute Direct Messages its target.
+
+        Parameters
+        ------------
+        enabled: bool (optional)
+            This parameter, if set, will toggle this setting to either True or False."""
         old_value = await self.config.guild(ctx.guild).dm()
         if enabled:
             await self.config.guild(ctx.guild).dm.set(enabled)