docs/devel: add some front matter to the devel index

Give an overview of the most useful bits of the devel documentation to
read depending on what the developer wants to do.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-23-alex.bennee@linaro.org>

docs/devel/index-process.rst

@@ -1,3 +1,5 @@
+.. _development_process:
+
 QEMU Community Processes
 ------------------------
 

docs/devel/index-tcg.rst

@@ -1,3 +1,5 @@
+.. _tcg:
+
 TCG Emulation
 -------------
 

docs/devel/index.rst

@@ -2,10 +2,30 @@
 Developer Information
 ---------------------
 
-This section of the manual documents various parts of the internals of QEMU.
-You only need to read it if you are interested in reading or
+This section of the manual documents various parts of the internals of
+QEMU. You only need to read it if you are interested in reading or
 modifying QEMU's source code.
 
+QEMU is a large and mature project with a number of complex subsystems
+that can be overwhelming to understand. The development documentation
+is not comprehensive but hopefully presents enough to get you started.
+If there are areas that are unclear please reach out either via the
+IRC channel or mailing list and hopefully we can improve the
+documentation for future developers.
+
+All developers will want to familiarise themselves with
+:ref:`development_process` and how the community interacts. Please pay
+particular attention to the :ref:`coding-style` and
+:ref:`submitting-a-patch` sections to avoid common pitfalls.
+
+If you wish to implement a new hardware model you will want to read
+through the :ref:`qom` documentation to understand how QEMU's object
+model works.
+
+Those wishing to enhance or add new CPU emulation capabilities will
+want to read our :ref:`tcg` documentation, especially the overview of
+the :ref:`tcg_internals`.
+
 .. toctree::
    :maxdepth: 1
 

docs/devel/tcg.rst

@@ -1,3 +1,5 @@
+.. _tcg_internals:
+
 ====================
 Translator Internals
 ====================