Update instruction.md

Add alternative words for the badge when HTML is applied

Author: yanghanlin

externals/instruction.md

@@ -3,12 +3,12 @@ Add a badge
 Add a badge to your awesome project by pasting this line in your README.md.
 
 ```html
-<a href="https://996.icu"><img src="https://img.shields.io/badge/link-996.icu-red.svg"></a>
+<a href="https://996.icu"><img src="https://img.shields.io/badge/link-996.icu-red.svg" alt="996.icu"></a>
 ```
 
 or equivalent Markdown code
 
 ```markdown
 [![996.icu](https://img.shields.io/badge/link-996.icu-red.svg)](https://996.icu)
 ```
-<a href="https://996.icu"><img src="https://img.shields.io/badge/link-996.icu-red.svg"></a>
+<a href="https://996.icu"><img src="https://img.shields.io/badge/link-996.icu-red.svg" alt="996.icu"></a>