docs: Move the GIOModule and GIOExtensionPoint SECTIONs

Move them to the struct docs.

Signed-off-by: Philip Withnall <pwithnall@gnome.org>

Helps: #3037

gio/giomodule.c

@@ -77,53 +77,47 @@
 #undef __GLIB_H_INSIDE__
 
 /**
- * SECTION:giomodule
- * @short_description: Loadable GIO Modules
- * @include: gio/gio.h
+ * GIOModule:
  *
  * Provides an interface and default functions for loading and unloading 
  * modules. This is used internally to make GIO extensible, but can also
  * be used by others to implement module loading.
- * 
- **/
+ */
 
 /**
- * SECTION:extensionpoints
- * @short_description: Extension Points
- * @include: gio.h
- * @see_also: [Extending GIO][extending-gio]
+ * GIOExtensionPoint:
  *
- * #GIOExtensionPoint provides a mechanism for modules to extend the
+ * `GIOExtensionPoint` provides a mechanism for modules to extend the
  * functionality of the library or application that loaded it in an 
- * organized fashion.  
+ * organized fashion.
  *
  * An extension point is identified by a name, and it may optionally
  * require that any implementation must be of a certain type (or derived
- * thereof). Use g_io_extension_point_register() to register an
- * extension point, and g_io_extension_point_set_required_type() to
+ * thereof). Use [func@Gio.IOExtensionPoint.register] to register an
+ * extension point, and [method@Gio.IOExtensionPoint.set_required_type] to
  * set a required type.
  *
- * A module can implement an extension point by specifying the #GType 
- * that implements the functionality. Additionally, each implementation
- * of an extension point has a name, and a priority. Use
- * g_io_extension_point_implement() to implement an extension point.
+ * A module can implement an extension point by specifying the
+ * [type@GObject.Type] that implements the functionality. Additionally, each
+ * implementation of an extension point has a name, and a priority. Use
+ * [func@Gio.IOExtensionPoint.implement] to implement an extension point.
  * 
- *  |[<!-- language="C" -->
- *  GIOExtensionPoint *ep;
+ * ```c
+ * GIOExtensionPoint *ep;
  *
- *  // Register an extension point
- *  ep = g_io_extension_point_register ("my-extension-point");
- *  g_io_extension_point_set_required_type (ep, MY_TYPE_EXAMPLE);
- *  ]|
+ * // Register an extension point
+ * ep = g_io_extension_point_register ("my-extension-point");
+ * g_io_extension_point_set_required_type (ep, MY_TYPE_EXAMPLE);
+ * ```
  *
- *  |[<!-- language="C" -->
- *  // Implement an extension point
- *  G_DEFINE_TYPE (MyExampleImpl, my_example_impl, MY_TYPE_EXAMPLE)
- *  g_io_extension_point_implement ("my-extension-point",
- *                                  my_example_impl_get_type (),
- *                                  "my-example",
- *                                  10);
- *  ]|
+ * ```c
+ * // Implement an extension point
+ * G_DEFINE_TYPE (MyExampleImpl, my_example_impl, MY_TYPE_EXAMPLE)
+ * g_io_extension_point_implement ("my-extension-point",
+ *                                 my_example_impl_get_type (),
+ *                                 "my-example",
+ *                                 10);
+ * ```
  *
  *  It is up to the code that registered the extension point how
  *  it uses the implementations that have been associated with it.
@@ -133,7 +127,7 @@
  *
  *  To avoid opening all modules just to find out what extension
  *  points they implement, GIO makes use of a caching mechanism,
- *  see [gio-querymodules][gio-querymodules].
+ *  see [gio-querymodules](gio-querymodules.html).
  *  You are expected to run this command after installing a
  *  GIO module.
  *
@@ -267,12 +261,6 @@ struct _GIOExtension {
   gint priority;
 };
 
-/**
- * GIOExtensionPoint:
- *
- * #GIOExtensionPoint is an opaque data structure and can only be accessed
- * using the following functions.
- */
 struct _GIOExtensionPoint {
   GType required_type;
   char *name;

gio/giomodule.h

@@ -49,11 +49,6 @@ void               g_io_module_scope_block   (GIOModuleScope      *scope,
 #define G_IO_IS_MODULE_CLASS(k)  (G_TYPE_CHECK_CLASS_TYPE ((k), G_IO_TYPE_MODULE))
 #define G_IO_MODULE_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), G_IO_TYPE_MODULE, GIOModuleClass))
 
-/**
- * GIOModule:
- *
- * Opaque module base class for extending GIO.
- **/
 typedef struct _GIOModuleClass GIOModuleClass;
 
 GIO_AVAILABLE_IN_ALL