gdk: Fill in some blanks in the docs

This is just an initial cut; more work is needed.

gdk/gdkclipboard.c

@@ -30,6 +30,20 @@
 #include "gdkpipeiostreamprivate.h"
 #include "gdktexture.h"
 
+/**
+ * SECTION:gdkclipboard
+ * @Short_description: Share data between applications for Copy-and-Paste
+ * @Title: Clipboards
+ * @See_also: #GdkContentProvider, #GdkContentFormats
+ *
+ * The #GdkClipboard object represents a clipboard of data shared
+ * between different applications or between different parts of
+ * the same application.
+ *
+ * To get a GdkClipboard object, use gdk_display_get_clipboard() or
+ * gdk_display_get_primary_clipboard().
+ */
+
 typedef struct _GdkClipboardPrivate GdkClipboardPrivate;
 
 struct _GdkClipboardPrivate
@@ -453,7 +467,7 @@ gdk_clipboard_get_formats (GdkClipboard *clipboard)
  * gdk_clipboard_is_local:
  * @clipboard: a #GdkClipboard
  *
- * Returns if the clipboard is local. A clipboard is consideredlocal if it was
+ * Returns if the clipboard is local. A clipboard is considered local if it was
  * last claimed by the running application.
  *
  * Note that gdk_clipboard_get_content() may return %NULL even on a local

gdk/gdkcontentdeserializer.c

@@ -26,6 +26,17 @@
 
 #include <gdk-pixbuf/gdk-pixbuf.h>
 
+
+/**
+ * SECTION:gdkcontentdeserializer
+ * @Short_description: Deserialize content for transfer
+ * @Title: GdkContentSerializer
+ * @See_also: #GdkContentDeserializer
+ *
+ * A GdkContentDeserializer is used to deserialize content for inter-application
+ * data transfers.
+ */
+
 typedef struct _Deserializer Deserializer;
 
 struct _Deserializer 

gdk/gdkcontentformats.c

@@ -20,7 +20,7 @@
  * @Title: Content Formats
  * @Short_description: Advertising and negotiating of content
  *     exchange formats
- * @See_also: #GdkDragContext, #GdkClipboard
+ * @See_also: #GdkDragContext, #GdkClipboard, #GdkContentProvider
  *
  * This section describes the #GdkContentFormats structure that is used to
  * advertise and negotiate the format of content passed between different

gdk/gdkcontentprovider.c

@@ -24,6 +24,15 @@
 #include "gdkcontentformats.h"
 #include "gdkintl.h"
 
+/**
+ * SECTION:gdkcontentprovider
+ * @Short_description: Provides content for data transfer between applications
+ * @Title: GdkContentProvider
+ *
+ * A GdkContentProvider is used to provide content for the clipboard in
+ * a number of formats.
+ */
+
 typedef struct _GdkContentProviderPrivate GdkContentProviderPrivate;
 
 struct _GdkContentProviderPrivate

gdk/gdkcontentserializer.c

@@ -28,6 +28,17 @@
 #include <gdk-pixbuf/gdk-pixbuf.h>
 #include <string.h>
 
+
+/**
+ * SECTION:gdkcontentserializer
+ * @Short_description: Serialize content for transfer
+ * @Title: GdkContentSerializer
+ * @See_also: #GdkContentDeserializer, #GdkContentProvider
+ *
+ * A GdkContentSerializer is used to serialize content for inter-application
+ * data transfers.
+ */
+
 typedef struct _Serializer Serializer;
 
 struct _Serializer 

gdk/gdktexture.c

@@ -17,7 +17,7 @@
  */
 
 /**
- * SECTION:GdkTexture
+ * SECTION:textures
  * @Title: GdkTexture
  * @Short_description: Pixel data
  *

gdk/gdkvulkancontext.c

@@ -28,6 +28,22 @@
 #include "gdkinternals.h"
 #include "gdkintl.h"
 
+/**
+ * SECTION:gdkvulkancontext
+ * @Title: GdkVulkanContext
+ * @Short_description: Vulkan context
+ *
+ * #GdkVulkanContext is an object representing the platform-specific
+ * Vulkan drawing context.
+ *
+ * #GdkVulkanContexts are created for a #GdkWindow using
+ * gdk_window_create_vulkan_context(), and the context will match the
+ * the characteristics of the window.
+ *
+ * Support for #GdkGLContext is platform-specific, context creation
+ * can fail, returning %NULL context.
+ */
+
 typedef struct _GdkVulkanContextPrivate GdkVulkanContextPrivate;
 
 struct _GdkVulkanContextPrivate {