[RFC] doc: restructure the introduction

[Stephen Hemminger <stephen@networkplumber.org>]

Add an about DPDK section (taken from web site), and a glossary.
Split the Programmer's Guide and Devices section.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
Rough draft as starting point.
Need to also cleanup headers of the sub-sections

 doc/guides/glossary/index.rst | 26 ++++++++++++++++++++++++++
 doc/guides/index.rst          | 35 ++++++++++++++++++++++++++++++-----
 2 files changed, 56 insertions(+), 5 deletions(-)
 create mode 100644 doc/guides/glossary/index.rst

diff --git a/doc/guides/glossary/index.rst b/doc/guides/glossary/index.rst
new file mode 100644
index 0000000000..5da74758b0
--- /dev/null
+++ b/doc/guides/glossary/index.rst
@@ -0,0 +1,26 @@
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright 2024 The DPDK contributors
+
+Glossary of Terms
+==================
+
+EAL
+  Environment Abstraction Layer. Originally used to isolate differences between running
+  on bare metal versus running as a userspace process. Bare metal is no longer supported.
+  Now used to provide abstraction across operating system envrionments.
+
+Process
+  An operating system process consisting of one or more threads.
+
+Thread
+  The unit of execution in the operating system. A thread maybe bound to a specific physical
+  core on the CPU or migrate among core's via the operating system scheduler.
+
+Lcore
+  A logical core. In DPDK lcore's are usually bound to a isolated physical CPU core.
+
+Isolated core
+  A core is isolated if it is reserved by the operating system and not used for normal
+  (muggle) processes. The operating system scheduler will not migrate a thread onto an
+  isolated core; the only way a thread will run on an isolated core is by requesting
+  affinity to that core.
diff --git a/doc/guides/index.rst b/doc/guides/index.rst
index 244b99624c..ed3557f070 100644
--- a/doc/guides/index.rst
+++ b/doc/guides/index.rst
@@ -1,20 +1,48 @@
 ..  SPDX-License-Identifier: BSD-3-Clause
     Copyright(c) 2010-2019 Intel Corporation.
 
-DPDK documentation
-==================
+############################################
+What is the Dataplane Development Kit (DPDK)
+############################################
+
+The Dataplane Development Kit (DPDK) is a set of libraries to accelerate packet processing
+workloads running on a wide variety of CPU architectures.
+
+Network performance, throughput, and latency are crucial for diverse applications, including wireless and wireline infrastructure, routers, load balancers, firewalls, video streaming, and VoIP. DPDK (Data Plane Development Kit), an open source project hosted by the Linux Foundation, provides a robust framework that boosts packet processing speeds on various CPU architectures like Intel x86, ARM, and PowerPC. This framework is key to rapidly developing high-speed data packet networking applications.
+
+By running DPDK, new users can significantly accelerate their network applications’ performance due to its efficient run-to-completion model and optimized libraries that ensure all necessary resources are allocated upfront.
 
 .. toctree::
+   :caption: About DPDK
+   :maxdepth: 1
+
+   glossary/index
+   contributing/index
+   rel_notes/index
+   faq/index
+
+.. toctree::
+   :caption: Getting Started
    :maxdepth: 1
 
    linux_gsg/index
    freebsd_gsg/index
    windows_gsg/index
    sample_app_ug/index
+
+.. toctree::
+   :caption: Programmers Guide
+   :maxdepth: 1
+
    prog_guide/index
    howto/index
    tools/index
    testpmd_app_ug/index
+
+.. toctree::
+   :caption: Device Drivers
+   :maxdepth: 1
+
    nics/index
    bbdevs/index
    cryptodevs/index
@@ -28,6 +56,3 @@ DPDK documentation
    rawdevs/index
    mempool/index
    platform/index
-   contributing/index
-   rel_notes/index
-   faq/index
-- 
2.45.2