[gtk-web] Update index.md

[Emmanuele Bassi <ebassi src gnome org>]

commit 20022ce77dc00ee94bb05a508c0ba8b0a78cf98b
Author: Emmanuele Bassi <ebassi gmail com>
Date:   Fri Mar 19 16:52:46 2021 +0000

    Update index.md
    
    Use up to date links for various libraries.

 _docs/apis/index.md | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)
---
diff --git a/_docs/apis/index.md b/_docs/apis/index.md
index dcd3eaa..1d095ef 100644
--- a/_docs/apis/index.md
+++ b/_docs/apis/index.md
@@ -6,11 +6,11 @@ application development.
 
 ### User interface and display
 
- - [GTK](https://developer.gnome.org/gtk4/stable/) — Widget toolkit for graphical interfaces
- - [GDK](https://developer.gnome.org/gdk4/stable/) — Low-level abstraction for the windowing system
- - [GSK](https://developer.gnome.org/gsk4/stable/) — Low-level scene graph and 3D rendering API
- - [Cairo](https://developer.gnome.org/cairo/stable/) — 2D, vector-based drawing for high-quality graphics
+ - [GTK](https://docs.gtk.org/gtk4/) — Widget toolkit for graphical interfaces
+ - [GDK](https://docs.gtk.org/gdk4/) — Low-level abstraction for the windowing system
+ - [GSK](https://docs.gtk.org/gsk4/) — Low-level scene graph and 3D rendering API
  - [Pango](https://developer.gnome.org/pango/stable/) — International text rendering with full Unicode 
support
+ - [Cairo](https://www.cairographics.org/manual/) — 2D, vector-based drawing for high-quality graphics
  - [ATK](https://developer.gnome.org/atk/stable/) — Accessibility toolkit to implement support for screen 
readers and other tools (GTK3 only)
 
 ### Storage of the user's data
@@ -28,13 +28,21 @@ application development.
 
 ### Multimedia
 
- - [GStreamer](https://developer.gnome.org/gstreamer-libs/stable/) — Playing, mixing, and manipulating sound 
and video
+ - [GStreamer](https://gstreamer.freedesktop.org/documentation/gstreamer/gi-index.html) — Playing, mixing, 
and manipulating sound and video
 
 ### Inter-process communication
 
  - [D-Bus](https://developer.gnome.org/gio/stable/gdbus-convenience.html) — Inter-process communication bus 
to provide APIs to other processes
  - [Polkit](https://www.freedesktop.org/software/polkit/docs/latest/) — Access control for system-level 
services provided through D-Bus
 
+### Asynchronous tasks
+
+ - [GTask](https://developer.gnome.org/gio/stable/GTask.html) – Cancellable synchronous or asynchronous task 
and result
+
+### Application support
+
+ - [GApplication](https://developer.gnome.org/gio/stable/application.html) — Writing applications
+
 ### Foundational C utilities and object system
 
  - [GLib](https://developer.gnome.org/glib/stable/) — Data structures and utilities for C programs