docs: Move the GStringChunk SECTION

Move the contents to the struct docs.

Helps: #3037

glib/gstringchunk.c

@@ -42,40 +42,33 @@
 #include "gutilsprivate.h"
 
 /**
- * SECTION:string_chunks
- * @title: String Chunks
- * @short_description: efficient storage of groups of strings
+ * GStringChunk:
+ *
+ * `GStringChunk` provides efficient storage of groups of strings
  *
  * String chunks are used to store groups of strings. Memory is
- * allocated in blocks, and as strings are added to the #GStringChunk
+ * allocated in blocks, and as strings are added to the `GStringChunk`
  * they are copied into the next free position in a block. When a block
  * is full a new block is allocated.
  *
  * When storing a large number of strings, string chunks are more
- * efficient than using g_strdup() since fewer calls to malloc() are
- * needed, and less memory is wasted in memory allocation overheads.
+ * efficient than using [func@g_strdup] since fewer calls to `malloc()`
+ * are needed, and less memory is wasted in memory allocation overheads.
  *
- * By adding strings with g_string_chunk_insert_const() it is also
+ * By adding strings with [method@GLib.StringChunk.insert_const] it is also
  * possible to remove duplicates.
  *
- * To create a new #GStringChunk use g_string_chunk_new().
+ * To create a new `GStringChunk` use [method@GLib.StringChunk.new].
  *
- * To add strings to a #GStringChunk use g_string_chunk_insert().
+ * To add strings to a `GStringChunk` use [method@GLib.Stringchunk.insert].
  *
- * To add strings to a #GStringChunk, but without duplicating strings
- * which are already in the #GStringChunk, use
- * g_string_chunk_insert_const().
+ * To add strings to a `GStringChunk`, but without duplicating strings
+ * which are already in the `GStringChunk`, use [method@GLib.StringChunk.insert_const].
  *
- * To free the entire #GStringChunk use g_string_chunk_free(). It is
- * not possible to free individual strings.
+ * To free the entire `GStringChunk` use [method@GLib.Stringchunk.free].
+ * It is not possible to free individual strings.
  */
 
-/**
- * GStringChunk:
- *
- * An opaque data structure representing String Chunks.
- * It should only be accessed by using the following functions.
- */
 struct _GStringChunk
 {
   GHashTable *const_table;