Apply suggestions from code review

Co-authored-by: Clay John <[email protected]>

tutorials/shaders/introduction_to_shaders.rst

@@ -112,7 +112,7 @@ Processor functions
 Depending on the shader type, you can override different processor functions.
 For ``spatial`` and ``canvas_item``, you have access to ``vertex()``,
 ``fragment()``, and ``light()``. For ``particles``, you only have access to
-``vertex()``.
+``vertex()``. For ''sky'', you only have access to ''fragment()''.
 
 Vertex processor
 ^^^^^^^^^^^^^^^^
@@ -134,9 +134,8 @@ Fragment processor
 ^^^^^^^^^^^^^^^^^^
 
 The ``fragment()`` processing function is used to set up the Godot material
-
 parameters per pixel. This code runs on every visible pixel the object or
-primitive draws. It is only available in ``spatial`` and ``canvas_item`` shaders.
+primitive draws. It is only available in ``spatial``, ``canvas_item``, and ``sky`` shaders.
 
 The standard use of the fragment function is to set up material properties used
 to calculate lighting. For example, you would set values for ``ROUGHNESS``,