ref-manual: tasks.rst: add reference to the "do_image_complete" task

(From yocto-docs rev: ebaf978cb7e682b724d9993cd0cd739ecb1c52b5)

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Reported-by: Quentin Schulz <foss@0leil.net>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/tasks.rst

@@ -146,13 +146,13 @@ section in the Yocto Project Overview and Concepts Manual.
 ``do_image_complete``
 ---------------------
 
-Completes the image generation process. The ``do_image_complete`` task
+Completes the image generation process. The :ref:`do_image_complete <ref-tasks-image-complete>` task
 runs after the OpenEmbedded build system has run the
 :ref:`ref-tasks-image` task during which image
 pre-processing occurs and through dynamically generated :ref:`do_image_* <ref-tasks-image>`
 tasks the image is constructed.
 
-The ``do_image_complete`` task performs post-processing on the image
+The :ref:`do_image_complete <ref-tasks-image-complete>` task performs post-processing on the image
 through the
 :term:`IMAGE_POSTPROCESS_COMMAND`.