Add main plugin class and init method

src/class-wp-asciinema-plugin.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * Main Plugin Class
+ *
+ * Coordinates integration with WordPress
+ */
+class WP_Asciinema_Plugin {
+
+	public function init() {
+	}
+}
+

src/loader.php

@@ -3,3 +3,6 @@
  * Imports and loads the various files needed for this plugin
  */
 
+// Main Plugin
+require 'class-wp-asciinema-plugin.php';
+

wp-asciinema.php

@@ -29,3 +29,6 @@ if ( ! defined( 'WPINC' ) ) {
 
 require __DIR__ . '/src/loader.php';
 
+$wp_asciinema = new WP_Asciinema_Plugin;
+$wp_asciinema->init();
+