doc: stepper: update stepper documentation

This commit adds documentation about stepper api along
with some minor cleanups

Signed-off-by: Jilay Pandya <jilay.pandya@zeiss.com>

doc/hardware/peripherals/stepper.rst

@@ -1,24 +1,65 @@
 .. _stepper_api:
 
-Stepper API
-###########
+Steppers
+########
 
-Overview
-********
+The stepper driver API provides a set of functions for controlling and configuring stepper drivers.
 
-The Stepper API provides a set of functions for controlling and configuring stepper motors.
-It supports a variety of operations, including enabling/disabling the controller, setting the
-target position of the motor and thereby setting the motor in motion, setting/getting the actual
-position of the motor and so on.
+Configure Stepper Driver
+========================
 
-Configuration Options
-*********************
+- Configure **micro-stepping resolution** using :c:func:`stepper_set_micro_step_res`
+  and :c:func:`stepper_get_micro_step_res`.
+- Configure **actual position a.k.a step count** in microsteps using :c:func:`stepper_set_actual_position`
+  and :c:func:`stepper_get_actual_position`.
+- Set **max velocity** in micro-steps per second using :c:func:`stepper_set_max_velocity`
+- **Enable** the stepper driver using :c:func:`stepper_enable`.
 
-Related configuration options:
+Control Stepper
+===============
 
-* :kconfig:option:`CONFIG_STEPPER_INIT_PRIORITY`
+- **Move by** +/- micro-steps also known as **relative movement** using :c:func:`stepper_move`.
+- **Move to** a specific position also known as **absolute movement**
+  using :c:func:`stepper_set_target_position`.
+- Run continuously with a **constant velocity** in a specific direction until
+  a stop is detected using :c:func:`stepper_enable_constant_velocity_mode`.
+- Check if the stepper is **moving** using :c:func:`stepper_is_moving`.
+
+Device Tree
+===========
+
+In the context of stepper controllers  device tree provides the initial hardware
+configuration for stepper drivers on a per device level. Each device must specify
+a device tree binding in Zephyr, and ideally, a set of hardware configuration options
+for things such as current settings, ramp parameters and furthermore. These can then
+be used in a boards devicetree to configure a stepper driver to its initial state.
+
+See examples in:
+
+- :dtcompatible:`adi,tmc5041`
+
+Discord
+=======
+
+Zephyr has a `stepper discord`_ channel for stepper related discussions, which
+is open to all.
+
+.. _stepper-api-reference:
 
 API Reference
 *************
 
+A common set of functions which should be implemented by all stepper drivers.
+
 .. doxygengroup:: stepper_interface
+
+Stepper controller specific APIs
+********************************
+
+Trinamic
+========
+
+.. doxygengroup:: trinamic_stepper_interface
+
+.. _stepper discord:
+   https://discord.com/channels/720317445772017664/1278263869982375946