Change events naming convention and split js code

Public/socket.js

@@ -0,0 +1,30 @@
+var socket = io('http://192.168.0.25:3333');
+
+function renderMessage(message) {
+    $('#messages').append(`<li class="list-group-item"><strong>${message.author}:</strong> ${message.content}</li>`);
+}
+
+socket.on('previous-messages', function (messages) {
+    for (message of messages) {
+        renderMessage(message);
+    }
+});
+
+socket.on('receive-message', function (message) {
+    renderMessage(message);
+});
+
+$('#chat').submit(function (event) {
+    event.preventDefault();
+
+    var author = $('input[name=username]').val();
+    var content = $('textarea[name=message]').val();
+
+    if (author.length && content.length) {
+        var messageObj = { author, content }
+    }
+
+    renderMessage(messageObj);
+
+    socket.emit('send-message', messageObj);
+});