translation: Update terminology and improve readability in preface su…

…mmary (#954)

* Update terminology and improve readability in preface summary

This commit made a few adjustments in the 'summary.md' file for clearer and more accessible language. "Brushing tool library" was replaced with "Coding Toolkit" to better reflect common terminology. Also, advice for beginners in algorithm learning journey was reformulated to imply a more positive approach avoiding detours and common pitfalls. The section related to the discussion forum was rewritten to sound more inviting to readers.

* Format

docs-en/chapter_preface/summary.md

@@ -1,8 +1,8 @@
 # Summary
 
-- The main audience of this book is beginners in algorithm. If you already have some basic knowledge, this book can help you systematically review your algorithm knowledge, and the source code in this book can also be used as a "brushing tool library".
+- The main audience of this book is beginners in algorithm. If you already have some basic knowledge, this book can help you systematically review your algorithm knowledge, and the source code in this book can also be used as a "Coding Toolkit".
 - The book consists of three main sections, Complexity Analysis, Data Structures, and Algorithms, covering most of the topics in the field.
-- For newcomers to algorithms, it is crucial to read an introductory book in the beginning stages to take the road less traveled.
+- For newcomers to algorithms, it is crucial to read an introductory book in the beginning stages to avoid many detours or common pitfalls.
 - Animations and graphs within the book are usually used to introduce key points and difficult knowledge. These should be given more attention when reading the book.
 - Practice is the best way to learn programming. It is highly recommended that you run the source code and type in the code yourself.
-- Each chapter in the web version of the book has a discussion forum, so feel free to share your doubts and insights.
+- Each chapter in the web version of this book features a discussion forum, and you are welcome to share your questions and insights at any time.