Fix the description of the wintertodt plugin and add boss tag

🙂

https://oldschool.runescape.wiki/w/Wintertodt

runelite-client/src/main/java/net/runelite/client/plugins/wintertodt/WintertodtPlugin.java

@@ -71,8 +71,8 @@ import net.runelite.client.util.ColorUtil;
 
 @PluginDescriptor(
 	name = "Wintertodt",
-	description = "Show helpful information for the Wintertodt minigame",
-	tags = {"minigame", "firemaking"}
+	description = "Show helpful information for the Wintertodt boss",
+	tags = {"minigame", "firemaking", "boss"}
 )
 @Slf4j
 public class WintertodtPlugin extends Plugin
@@ -473,4 +473,4 @@ public class WintertodtPlugin extends Plugin
 				return 0;
 		}
 	}
-}
+}