List known reactions

main.js

@@ -120,6 +120,10 @@ const commands = {
         db.get("messageReactions").unset(content).write();
         msg.channel.send(`${msg.author.toString()} Removed reaction!`);
     },
+    "reactions": msg => {
+        let reactions = db.get("messageReactions").keys().value().reduce((p, c) => `${p}\n${c}`, "");
+        msg.channel.send(`I'll react to the following messages:\n\`\`\`${reactions}\`\`\``);
+    },
     "help": msg => {
         let guides = db
             .get("guides")