doc: Use new Sphinx extension for code samples

Use the new code-sample directive and roles in a few places
to demonstrate how it works.

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>

boards/arm/nrf52_adafruit_feather/doc/index.rst

@@ -169,7 +169,7 @@ the board are working properly with Zephyr:
 - :ref:`blinky-sample`
 - :ref:`button-sample`
 - :ref:`fade-led-sample`
-- :ref:`blink-led-sample`
+- :ref:`pwm-blinky-sample`
 - :ref:`96b_carbon_multi_thread_blinky`
 
 You can build and flash the examples to make sure Zephyr is running correctly on

samples/basic/blinky/README.rst

@@ -1,7 +1,8 @@
-.. _blinky-sample:
+.. zephyr:code-sample:: blinky-sample
+   :name: Blinky
+   :relevant-api: gpio_interface
 
-Blinky
-######
+   Blink an LED forever using the GPIO API.
 
 Overview
 ********
@@ -15,7 +16,7 @@ The source code shows how to:
 #. Configure the GPIO pin as an output
 #. Toggle the pin forever
 
-See :ref:`pwm-blinky-sample` for a similar sample that uses the PWM API instead.
+See :zephyr:code-sample:`pwm-blinky-sample` for a similar sample that uses the PWM API instead.
 
 .. _blinky-sample-requirements:
 

samples/basic/blinky_pwm/README.rst

@@ -1,14 +1,14 @@
-.. _blink-led-sample:
-.. _pwm-blinky-sample:
+.. zephyr:code-sample:: pwm-blinky-sample
+   :name: PWM Blinky
+   :relevant-api: pwm_interface
 
-PWM Blinky
-##########
+   Blink an LED using the PWM API.
 
 Overview
 ********
 
-This application blinks a LED using the :ref:`PWM API <pwm_api>`. See
-:ref:`blinky-sample` for a GPIO-based sample.
+This application blinks an LED using the :ref:`PWM API <pwm_api>`. See
+:zephyr:code-sample:`blinky-sample` for a GPIO-based sample.
 
 The LED starts blinking at a 1 Hz frequency. The frequency doubles every 4
 seconds until it reaches 128 Hz. The frequency will then be halved every 4

samples/basic/button/README.rst

@@ -1,7 +1,8 @@
-.. _button-sample:
+.. zephyr:code-sample:: button-sample
+   :name: Button
+   :relevant-api: gpio_interface
 
-Button
-######
+   Handle GPIO inputs with interrupts.
 
 Overview
 ********
@@ -27,7 +28,7 @@ You may see additional build errors if the ``sw0`` alias exists, but is not
 properly defined.
 
 The sample additionally supports an optional ``led0`` devicetree alias. This is
-the same alias used by the :ref:`blinky-sample`. If this is provided, the LED
+the same alias used by the :zephyr:code-sample:`blinky-sample`. If this is provided, the LED
 will be turned on when the button is pressed, and turned off off when it is
 released.
 

samples/basic/fade_led/README.rst

@@ -18,7 +18,7 @@ Requirements and Wiring
 ***********************
 
 This sample has the same requirements and wiring considerations as the
-:ref:`pwm-blinky-sample`.
+:zephyr:code-sample:`pwm-blinky-sample`.
 
 Building and Running
 ********************

samples/basic/hash_map/README.rst

@@ -1,7 +1,8 @@
-.. _system_hashmap:
+.. zephyr:code-sample:: system_hashmap
+   :name: System Hashmap
+   :relevant-api: hashmap_apis
 
-System Hashmap
-##############
+   Insert, replace, and remove entries in a hashmap.
 
 Overview
 ********

samples/bluetooth/encrypted_advertising/README.rst

@@ -25,8 +25,8 @@ Requirements
 ************
 
 * Two boards with Bluetooth Low Energy support
-* Two boards with a push button connected via a GPIO pin, see :ref:`Button
-  sample <button-sample>` for more details
+* Two boards with a push button connected via a GPIO pin, see :zephyr:code-sample:`button-sample`
+  for more details
 
 Building and Running
 ********************

samples/kernel/condition_variables/condvar/README.rst

@@ -1,12 +1,13 @@
-.. _samples_kernel_condvar:
+.. zephyr:code-sample:: kernel-condvar
+   :name: Condition Variables
+   :relevant-api: condvar_apis
 
-Condition Variables
-###################
+   Manipulate condition variables in a multithreaded application.
 
 Overview
 ********
 
-This sample demonstrates the usage of condition variables in a
+This sample demonstrates the usage of :ref:`condition variables <condvar>` in a
 multithreaded application. Condition variables are used with a mutex
 to signal changing states (conditions) from one thread to another
 thread. A thread uses a condition variable to wait for a condition to

samples/synchronization/README.rst

@@ -1,7 +1,8 @@
-.. _synchronization_sample:
+.. zephyr:code-sample:: synchronization_sample
+   :name: Synchronization Sample
+   :relevant-api: thread_apis semaphore_apis
 
-Synchronization Sample
-######################
+   Manipulate basic kernel synchronization primitives.
 
 Overview
 ********