Add a Doxyfile and preliminary module-level docs.

src/serialize.h

@@ -1,5 +1,12 @@
 #pragma once
 
+/**
+** \defgroup serialize JS binary serialization
+** Converts JS data to a basic binary format with support for exporting
+** functions so that they can be called across the barrier, too.
+** @{
+*/
+
 #include "quickjs.h"
 
 typedef struct _tf_task_t tf_task_t;
@@ -7,3 +14,5 @@ typedef struct _tf_taskstub_t tf_taskstub_t;
 
 void tf_serialize_store(tf_task_t* task, tf_taskstub_t* to, void** out_buffer, size_t* out_size, JSValue value);
 JSValue tf_serialize_load(tf_task_t* task, tf_taskstub_t* from, const char* buffer, size_t size);
+
+/** @} */