docs: Move the checkedmath SECTION

Move it to a separate Markdown file.

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

Helps: #3037

docs/reference/glib/checked-math.md

@@ -0,0 +1,30 @@
+Title: Bounds-checking Integer Arithmetic
+SPDX-License-Identifier: LGPL-2.1-or-later
+SPDX-FileCopyrightText: 2015 Allison Lortie
+
+# Bounds-checking Integer Arithmetic
+
+GLib offers a set of macros for doing additions and multiplications
+of unsigned integers, with checks for overflows.
+
+The helpers all have three arguments.  A pointer to the destination
+is always the first argument and the operands to the operation are
+the other two.
+
+Following standard GLib convention, the helpers return true in case
+of success (ie: no overflow).
+
+The helpers may be macros, normal functions or inlines.  They may be
+implemented with inline assembly or compiler intrinsics where
+available.
+
+Since: 2.48
+
+The APIs are:
+
+ * [func@GLib.uint_checked_add]
+ * [func@GLib.uint_checked_mul]
+ * [func@GLib.uint64_checked_add]
+ * [func@GLib.uint64_checked_mul]
+ * [func@GLib.size_checked_add]
+ * [func@GLib.size_checked_mul]

docs/reference/glib/glib.toml.in

@@ -68,6 +68,7 @@ content_files = [
   "reference-counting.md",
   "testing.md",
   "atomic.md",
+  "checked-math.md",
   "threads.md",
   "spawn.md",
   "unix.md",

docs/reference/glib/meson.build

@@ -149,6 +149,7 @@ expand_content_files = [
   'base64.md',
   'building.md',
   'character-set.md',
+  'checked-math.md',
   'compiling.md',
   'cross-compiling.md',
   'datalist-and-dataset.md',

glib/docs.c

@@ -1702,27 +1702,6 @@
  */
  
 /* Bounds-checked integer arithmetic {{{1 */
-/**
- * SECTION:checkedmath
- * @title: Bounds-checking integer arithmetic
- * @short_description: a set of helpers for performing checked integer arithmetic
- *
- * GLib offers a set of macros for doing additions and multiplications
- * of unsigned integers, with checks for overflows.
- *
- * The helpers all have three arguments.  A pointer to the destination
- * is always the first argument and the operands to the operation are
- * the other two.
- *
- * Following standard GLib convention, the helpers return %TRUE in case
- * of success (ie: no overflow).
- *
- * The helpers may be macros, normal functions or inlines.  They may be
- * implemented with inline assembly or compiler intrinsics where
- * available.
- *
- * Since: 2.48
- */
 
 /**
  * g_uint_checked_add