doc: dts: add missing entry to dts/bindings search path
Since SHIELD_DIRS gets added to DTS_ROOT in dts.cmake, any shield
directories are also places where we look for bindings by default.
This feature is not used in upstream Zephyr, but it is supported,
so document it.
Suggested-by: Jamie McCrae
@@ -115,7 +115,9 @@ subdirectories of the following places:
- the zephyr repository
- your :ref:`application source directory <application>`
- your :ref:`board directory <board_porting_guide>`
-- any directories in the :ref:`DTS_ROOT <dts_root>` CMake variable
+- any :ref:`shield directories <shields>`
+- any directories manually included in the :ref:`DTS_ROOT <dts_root>`
+ CMake variable
- any :ref:`module <modules>` that defines a ``dts_root`` in its
:ref:`modules_build_settings`
