Moderation plugin PR (#328)

* Moderation plugin PR

* fixed moderation plugin syntax error

* Update registry.json

Author: xPolar

plugins/registry.json

@@ -178,5 +178,14 @@
         "title": "Get Stats",
         "icon_url": "https://image.flaticon.com/icons/png/512/117/117761.png",
         "thumbnail_url": "http://www.pngmart.com/files/7/Statistics-PNG-Clipart.png"
-    }
+    },
+    "moderation":{
+        "repository": "xPolar/modmail-plugins/Moderation/",
+        "branch": "master",
+        "description": "Moderate your server with Modmail, bring the Mod to Modmail!",
+        "bot_version": "3.0.3",
+        "title": "Moderate your server",
+        "icon_url": "https://cdn.discordapp.com/attachments/539943767562780704/601485194196680704/wGFmzZq.png",
+        "thumbnail_url": "https://cdn.discordapp.com/attachments/539943767562780704/601485194196680704/wGFmzZq.png"
+    } 
 }