refactor: Update library section heading in README and docs

The code changes update the heading for the library section in both the README and docs files. The heading is changed from "Library" to "Libraries" to provide a more accurate description of the content. This refactor improves the clarity and consistency of the documentation.

README.md

@@ -107,7 +107,7 @@ var art = new Artplayer({
 -   [artplayer-plugin-vast](https://artplayer.org/?libs=./uncompiled/artplayer-plugin-vast/index.js&example=vast) (WIP)
 -   [artplayer-plugin-chapter](https://artplayer.org/?libs=./uncompiled/artplayer-plugin-chapter/index.js&example=chapter)
 
-## Library
+## Libraries
 
 -   [hls.js](https://artplayer.org/?libs=https://cdnjs.cloudflare.com/ajax/libs/hls.js/8.0.0-beta.3/hls.min.js&example=hls)
 -   [dash.js](https://artplayer.org/?libs=https://cdnjs.cloudflare.com/ajax/libs/dashjs/4.5.2/dash.all.min.js&example=dash)

docs/index.html

@@ -27,7 +27,7 @@
                 Ecosystem
                 <div class="sub-menu">
                     <ul>
-                        <li class="title">Library</li>
+                        <li class="title">Libraries</li>
                         <li style="display: inline-block;margin-right: 10px;">
                             <a
                                 href="/?libs=https://cdnjs.cloudflare.com/ajax/libs/hls.js/8.0.0-beta.3/hls.min.js&example=hls">hls.js</a>
@@ -97,7 +97,7 @@
                         </li>
                     </ul>
                     <ul>
-                        <li class="title">Proxy</li>
+                        <li class="title">Proxys</li>
                         <li>
                             <a
                                 href="/?libs=./uncompiled/artplayer-proxy-webav/index.js&example=webav">artplayer-proxy-webav</a>