Revisit the English version (#1885)

* Update giscus scroller.

* Refine English docs and landing page

* Sync the headings.

* Update landing pages.

* Update the avatar

* Update Acknowledgements

* Update landing pages.

* Update contributors.

* Update

* Fix the formula formatting.

* Fix the glossary.

* Chapter 6. Hashing

* Remove Chinese chars.

* Fix headings.

* Update giscus themes.

* fallback to default giscus theme to solve 429 many requests error.

* Add borders for callouts.

* docs: sync character encoding translations

* Update landing page media layout and i18n

docs/index.html

@@ -110,7 +110,7 @@
                     <div style="height: 8.17%;"></div>
                     <img class="device-on-hover" style="height: 66.83%;" src="assets/hero/cover_render.png" alt="Cover">
                     <div class="text-button">
-                        <span>获取纸质书</span>
+                        <span>了解纸质书</span>
                         <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 512">
                             <path d="M278.6 233.4c12.5 12.5 12.5 32.8 0 45.3l-160 160c-12.5 12.5-32.8 12.5-45.3 0s-12.5-32.8 0-45.3L210.7 256 73.4 118.6c-12.5-12.5-12.5-32.8 0-45.3s32.8-12.5 45.3 0l160 160z" />
                         </svg>
@@ -251,7 +251,7 @@
 
         <!-- code reviewers -->
         <div style="margin: 2em auto;">
-            <h3>代码译者</h3>
+            <h3>代码审阅者</h3>
             <p>本书多语言代码版本由以下开发者协力完成，感谢他们的投入与贡献！</p>
             <div class="profile-div">
                 <div class="profile-cell">