added express endpoints, a settings service and a media info service

src/constants/globalEvents.js

@@ -0,0 +1,9 @@
+const globalEvents = {
+  play: "play",
+  pause: "pause",
+  playPause: "playPause",
+  next: "next",
+  previous: "previous",
+};
+
+module.exports = globalEvents;

src/constants/mediaKeys.js

@@ -0,0 +1,9 @@
+const globalEvents = require("./globalEvents");
+
+const mediaKeys = {
+  MediaPlayPause: globalEvents.playPause,
+  MediaNextTrack: globalEvents.next,
+  MediaPreviousTrack: globalEvents.previous,
+};
+
+module.exports = mediaKeys;