QOL: Move source code under the src directory. (#1318)

src/types/player-api-events.ts

@@ -0,0 +1,15 @@
+export interface PlayerAPIEvents {
+  videodatachange: {
+    value: Record<string, unknown> & {
+      videoId: string
+      title: string
+      author: string
+
+      playlistId: string
+      isUpcoming: boolean
+      loading: boolean
+
+      lengthSeconds: number
+    }
+  } & ({ name: 'dataloaded' } | { name: 'dataupdated ' })
+}