Update references to the docs guidelines

We split some pages into two and some remaining references were leading to an
irrelevant page.

about/introduction.rst

@@ -102,7 +102,7 @@ relatively intuitive:
   which is also available directly within the engine's script editor. It is
   generated automatically from a file in the main source repository, therefore
   the generated files of the documentation are not meant to be modified. See
-  :ref:`doc_updating_the_class_reference` for details.
+  :ref:`doc_class_reference_writing_guidelines` for details.
 
 In addition to this documentation you may also want to take a look at the
 various `Godot demo projects <https://github.com/godotengine/godot-demo-projects>`_.

community/contributing/ways_to_contribute.rst

@@ -176,13 +176,13 @@ Contributing to the documentation
 
 There are two separate resources referred to as "documentation" in Godot:
 
--  **The class reference.** This is the documentation for the complete Godot
-   API as exposed to GDScript and the other scripting languages. It can be
-   consulted offline, directly in Godot's code editor, or online at
-   :ref:`Godot API <toc-class-ref>`.
-   To contribute to the class reference, you have to edit the
+- **The class reference.** This is the documentation for the complete Godot API
+   as exposed to GDScript and the other scripting languages. It can be consulted
+   offline, directly in Godot's code editor, or online at :ref:`Godot API
+   <toc-class-ref>`. To contribute to the class reference, you have to edit the
    `doc/base/classes.xml` in Godot's Git repository, and make a pull request.
-   See :ref:`doc_updating_the_class_reference` for more details.
+   See :ref:`doc_updating_the_class_reference` and
+   :ref:`doc_class_reference_writing_guidelines` for more details.
 
 -  **The tutorials and engine documentation and its translations.** This is the part you are reading
    now, which is distributed in the HTML, PDF and EPUB formats. Its contents

development/cpp/custom_modules_in_cpp.rst

@@ -573,7 +573,7 @@ Now if you go to the ``godot/modules/summator/doc_classes`` folder, you will see
 that it contains a ``Summator.xml`` file, or any other classes, that you referenced
 in your ``get_doc_classes`` function.
 
-Edit the file(s) following :ref:`doc_updating_the_class_reference` and recompile the engine.
+Edit the file(s) following :ref:`doc_class_reference_writing_guidelines` and recompile the engine.
 
 Once the compilation process is finished, the docs will become accessible within
 the engine's built-in documentation system.

tutorials/ui/bbcode_in_richtextlabel.rst

@@ -15,8 +15,9 @@ a :ref:`class_RichTextLabel`.
 :ref:`class_RichTextLabel` allows the display of complex text markup in a Control.
 It has a built-in API for generating the markup, but can also parse a BBCode.
 
-Note that the BBCode tags can also be used, to some extent, in the
-:ref:`XML source of the class reference <doc_updating_the_class_reference>`.
+Note that the BBCode tags can also be used, to some extent, in the XML source of
+the class reference. For more information, see
+:ref:`doc_class_reference_writing_guidelines`.
 
 Using BBCode
 ------------