Add note about line skips in the style guide

tutorials/scripting/gdscript/gdscript_styleguide.rst

@@ -254,6 +254,9 @@ Surround functions and class definitions with two blank lines:
 
 Use one blank line inside functions to separate logical sections.
 
+.. note:: We use a single line between classes and function definitions in the class reference and
+          in short code snippets in this documentation.
+
 Line length
 ~~~~~~~~~~~