doc: Promote design patterns to a top level section

doc/sphinx/index.rst

@@ -74,6 +74,7 @@ Longer listings like example command output and VCL look like this::
     tutorial/index.rst
     users-guide/index.rst
     reference/index.rst
+    vcl-design-patterns/index.rst
     whats-new/index.rst
     dev-guide/index.rst
     phk/index.rst

doc/sphinx/reference/index.rst

@@ -9,6 +9,8 @@
 The Varnish Reference Manual
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
+.. _reference-vcl:
+
 The VCL language
 ----------------
 
@@ -21,13 +23,8 @@ The VCL language
 	VCL backend health probe <vcl-probe>
 	states.rst
 
-VCL Design Patterns
--------------------
-
-.. toctree::
-	:maxdepth: 1
-
-	dp_vcl_resp_status.rst
+A collection of :ref:`vcl-design-patterns-index` is available in addition to
+these reference manuals.
 
 Bundled VMODs
 -------------

doc/sphinx/vcl-design-patterns/index.rst

+..
+	Copyright (c) 2021 Varnish Software AS
+	SPDX-License-Identifier: BSD-2-Clause
+	See LICENSE file for full text of license
+
+.. _vcl-design-patterns-index:
+
+%%%%%%%%%%%%%%%%%%%
+VCL Design Patterns
+%%%%%%%%%%%%%%%%%%%
+
+This section showcases design patterns for :ref:`reference-vcl`. To keep code
+examples short, some aspects not directly related to a given design pattern
+may be simplified.
+
+.. toctree::
+	:maxdepth: 1
+
+	resp-status.rst