Add the chapter of hello_algo (#1215)

* Add the chapter of hello_algo

* Remove the comment field from the landing page

* Update the link in the landing page

* Fix a typo

docs/index.html

@@ -80,7 +80,7 @@
             <p style="margin-top: max(-1vh, -2vw); margin-bottom: min(2vh, 3.5vw);">
                 动画图解、一键运行的数据结构与算法教程
             </p>
-            <a href="/chapter_preface/" class="rounded-button">
+            <a href="/chapter_hello_algo/" class="rounded-button">
                 <svg xmlns="http://www.w3.org/2000/svg"
                     viewBox="0 0 512 512"><!--!Font Awesome Free 6.5.1 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free Copyright 2024 Fonticons, Inc.-->
                     <path
@@ -153,7 +153,7 @@
                 </a>
             </div>
             <div class="media-block">
-                <a href="/chapter_preface/">
+                <a href="/chapter_hello_algo/">
                     <div style="height: 4.34%;"></div>
                     <img class="device-on-hover" style="height: 66.31%;" src="assets/hero/web_mac_iphone.png" alt="">
                     <div style="height: 4.34%;"></div>
@@ -354,17 +354,4 @@
             </a>
         </div>
     </div>
-</section>
-
-<!-- Section: comments -->
-<section data-md-color-scheme="default" data-md-color-primary="white" class="home-div">
-    <div class="section-content giscus-container">
-        <p>欢迎在评论区留下你的见解、问题或建议</p>
-        <!-- Insert generated snippet here -->
-        <script src="https://giscus.app/client.js" data-repo="krahets/hello-algo" data-repo-id="R_kgDOIXtSqw"
-            data-category="Announcements" data-category-id="DIC_kwDOIXtSq84CSZk_" data-mapping="pathname"
-            data-strict="1" data-reactions-enabled="1" data-emit-metadata="0" data-input-position="top"
-            data-theme="light" data-lang="zh-CN" crossorigin="anonymous" async>
-            </script>
-    </div>
 </section>