Update index.md

docs/index.md

@@ -18,7 +18,11 @@ hide:
 
 <p align="center">
   <a href="https://github.com/krahets/hello-algo">
-    <img alt="GitHub Repo stars" src="https://img.shields.io/github/stars/krahets/hello-algo?style=social&link=https%3A%2F%2Fgithub.com%2Fkrahets%2Fhello-algo">
+    <img alt="GitHub repo stars" src="https://img.shields.io/github/stars/krahets/hello-algo?style=social&link=https%3A%2F%2Fgithub.com%2Fkrahets%2Fhello-algo">
+  </a>
+  &nbsp;
+  <a href="https://github.com/krahets/hello-algo/releases">
+    <img alt="GitHub all releases" src="https://img.shields.io/github/downloads/krahets/hello-algo/total?style=social&logo=gitbook&logoColor=black&label=PDF%20Downloads">
   </a>
   &nbsp;
   <a href="https://github.com/krahets/hello-algo">
@@ -26,6 +30,22 @@ hide:
   </a>
 </p>
 
+<p align="center">
+  <img src="https://img.shields.io/badge/Python-snow?logo=python&logoColor=3776AB">
+  <img src="https://img.shields.io/badge/C%2B%2B-snow?logo=c%2B%2B&logoColor=00599C">
+  <img src="https://img.shields.io/badge/Java-snow?logo=coffeescript&logoColor=FC4C02">
+  <img src="https://img.shields.io/badge/C%23-snow?logo=csharp&logoColor=512BD4">
+  <img src="https://img.shields.io/badge/Go-snow?logo=go&logoColor=00ADD8">
+  <img src="https://img.shields.io/badge/Swift-snow?logo=swift&logoColor=F05138">
+  <img src="https://img.shields.io/badge/JavaScript-snow?logo=javascript&logoColor=E9CE30">
+  <img src="https://img.shields.io/badge/TypeScript-snow?logo=typescript&logoColor=3178C6">
+  <img src="https://img.shields.io/badge/Dart-snow?logo=dart&logoColor=0175C2">
+  <img src="https://img.shields.io/badge/Rust-snow?logo=rust&logoColor=000000">
+  <img src="https://img.shields.io/badge/C-snow?logo=c&logoColor=A8B9CC">
+  <img src="https://img.shields.io/badge/Zig-snow?logo=zig&logoColor=F7A41D">
+  <img src="https://img.shields.io/badge/Stay%20Tuned-snow">
+</p>
+
 ---
 
 <h2 align="center"> 推荐语 </h2>