docs: Move the gnetworking SECTION

Move it to a separate page.

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

Helps: #3037

docs/reference/gio/gio.toml.in

@@ -53,6 +53,8 @@ content_files = [
   "dbus-utils.md",
   "menu-exporter.md",
 
+  "networking.md",
+
   "migrating-gdbus.md",
   "migrating-gconf.md",
   "migrating-gnome-vfs.md",

docs/reference/gio/meson.build

@@ -237,6 +237,7 @@ expand_content_files = [
   'migrating-gconf.md',
   'migrating-gdbus.md',
   'migrating-gnome-vfs.md',
+  'networking.md',
   'overview.md',
   'tls-overview.md',
 ]

docs/reference/gio/networking.md

@@ -0,0 +1,29 @@
+Title: gnetworking.h
+SPDX-License-Identifier: LGPL-2.1-or-later
+SPDX-FileCopyrightText: 2010 Dan Winship
+
+# gnetworking.h
+
+The `<gio/gnetworking.h>` header can be included to get
+various low-level networking-related system headers, automatically
+taking care of certain portability issues for you.
+
+This can be used, for example, if you want to call
+[`setsockopt()`](man:setsockopt(2)) on a [class@Gio.Socket].
+
+Note that while WinSock has many of the same APIs as the
+traditional UNIX socket API, most of them behave at least slightly
+differently (particularly with respect to error handling). If you
+want your code to work under both UNIX and Windows, you will need
+to take these differences into account.
+
+Also, under GNU libc, certain non-portable functions are only visible
+in the headers if you define `_GNU_SOURCE` before including them. Note
+that this symbol must be defined before including any headers, or it
+may not take effect.
+
+There is one function provided specifically for initialising the networking
+APIs, which needs to be called only if they are being used before GLib
+initialises itself:
+
+ * [func@Gio.networking_init]

gio/gnetworking.c

@@ -25,31 +25,6 @@
 #include "gnetworking.h"
 #include "gnetworkingprivate.h"
 
-/**
- * SECTION:gnetworking
- * @title: gnetworking.h
- * @short_description: System networking includes
- * @include: gio/gnetworking.h
- *
- * The `<gio/gnetworking.h>` header can be included to get
- * various low-level networking-related system headers, automatically
- * taking care of certain portability issues for you.
- *
- * This can be used, for example, if you want to call setsockopt()
- * on a #GSocket.
- *
- * Note that while WinSock has many of the same APIs as the
- * traditional UNIX socket API, most of them behave at least slightly
- * differently (particularly with respect to error handling). If you
- * want your code to work under both UNIX and Windows, you will need
- * to take these differences into account.
- *
- * Also, under GNU libc, certain non-portable functions are only visible
- * in the headers if you define %_GNU_SOURCE before including them. Note
- * that this symbol must be defined before including any headers, or it
- * may not take effect.
- */
-
 /**
  * g_networking_init:
  *