docs: Improve introduction and add Amazon link (#374)

Adds a paragraph emphasizing the adaptability of technologists and the book's focus on tailoring the shell to individual needs.  Includes a link to pre-order the book on Amazon, with an image.  Minor re-ordering of content for clarity.

Author: dwmkerr

docs/00-index.mdx

@@ -9,28 +9,35 @@ sidebar_label: Introduction
 slug: '/'
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-:::tip Even More Effective Shell!
+One trait that defines great technologists is their ability to adapt their tools to their unique styles and needs. This book will help you do just that by using the shell. Investing a few hours in learning the command line techniques in Effective Shell will have a huge impact on your productivity. It will also make your work more fun.
 
-Check out my new project [Terminal AI](https://github.com/dwmkerr/terminal-ai) - a tool that lets you use AI directly from the shell 😊
+You can read this book online for free, or [pre-order Effective Shell in paperback or for Kindle](https://amzn.to/4ho0F91):
 
-:::
+<div style={{ textAlign: "center", width: "100%;" }}>
+<a href="https://amzn.to/4ho0F91" target="_blank"><img alt="Effective Shell" src="/images/es-amazon-cover.png" style={{ maxWidth: "240px" }} /></a>
+</div>
 
-Investing just a few hours in your ability to use text based interfaces for your computer can have an enormous impact on your productivity. It can also make your work more fun, allowing you to maintain that creative 'flow' state that can make technology so exciting.
-
-I've been lucky enough to spend many years working as a software engineer, but also with scientists, data engineers, site reliability engineers and technologists of all sorts. One thing that has stood out about great technologists has been their ability to make their tools work for them, stitching them together in creative ways that suits their style.
+The shell's simple text-based interface lets you maintain a state of creative flow, free from the distractions of a graphical environment.
 
 This is not a book on shell scripting or Linux administration! Each chapter in this book can be read as a standalone set of techniques to help you be more efficient, understand your system in more depth, and craft your environment to suit your working style. This book does not advocate that you totally change the way you work or drop your current tooling; it just brings together a set of skills that you can add to your toolkit and incorporate in your own way.
 
-<!-- manuscript:ignore:start -->
-If you find this book useful, please consider [donating](https://github.com/sponsors/dwmkerr?frequency=one-time&sponsor=dwmkerr) to support my open source work - just a one off contribution for a coffee helps!
-<!-- manuscript:ignore:end -->
+:::tip Even More Effective Shell!
+
+Check out my new project [Terminal AI](https://github.com/dwmkerr/terminal-ai) - a tool that lets you use AI directly from the shell 😊
+
+:::
+
 
 ## Who Should Read This Book
 
 Developers and engineers should find almost every chapter of this book immediately applicable in day-to-day work. Whether you use Python, Golang, .NET, Java, whether you use an IDE or the terminal, these skills will help in day-to-day work.
 
 Site reliability engineers, system administrators and DevSecOps professionals will find these skills essential - if you regularly administer remote machines, connect to containers, manage clusters or cloud environments, you will find many techniques to help you with your work.
 
+<!-- manuscript:ignore:start -->
+If you find this book useful, please consider [donating](https://github.com/sponsors/dwmkerr?frequency=one-time&sponsor=dwmkerr) to support my open source work - just a one off contribution for a coffee helps!
+<!-- manuscript:ignore:end -->
+
 Hobbyists, polymaths and explorers should also read on - as well as going into specific techniques, each chapter gives essential knowledge on how these computers, operating systems and networking works.
 
 ## What's In This Book?