Add note about TMC stepper drivers (#5085)

* Add note about TMC stepper drivers

* Fix formatting

* Update index.rst

---------

Co-authored-by: Djordje Mandic <[email protected]>

Author: ggodlewski

components/stepper/index.rst

@@ -81,6 +81,20 @@ Configuration variables:
               number: GPIOXX
               inverted: true
 
+.. note::
+
+    TMC drivers are pin-compatible with the A4988, but instead of a ``SLEEP`` pin they expose an ``ENABLE`` pin.  
+    When using a TMC driver with the ``a4988`` platform you therefore need to invert the ``sleep_pin``:
+
+    .. code-block:: yaml
+
+        stepper:
+          - platform: a4988
+            # ...
+            sleep_pin:
+              number: GPIOXX
+              inverted: true
+
 ULN2003 Component
 -----------------