Add a Doxyfile and preliminary module-level docs.

src/socket.js.h

@@ -1,7 +1,15 @@
 #pragma once
 
+/**
+** \defgroup socket_js Socket Interface
+** Exposes network sockets to script.
+** @{
+*/
+
 #include "quickjs.h"
 
 JSValue tf_socket_register(JSContext* context);
 int tf_socket_get_count();
 int tf_socket_get_open_count();
+
+/** @} */