Add timer show command

This command shows information about the timer with the ID you have as
an argument.

util/timer/showTimer.js

@@ -0,0 +1,12 @@
+const fs = require('fs');
+
+module.exports = function (client, authorID, timerID) {
+    let timerToShow = client.timers.find(timer => timer.ID === parseInt(timerID));
+    if (timerToShow === undefined)
+        return "Timer not found";
+    if (timerToShow.user !== authorID){
+        return "You can only show info about your own timers.";
+    }
+    return `${timerToShow.ID} will remind you <t:${timerToShow.reminderDate.toFixed(0)}:R> (<t:${timerToShow.reminderDate.toFixed(0)}:f>) with the message "${timerToShow.customMessage}"`;
+    
+}