doc: add the example link of webjs

Author: ksw2000

README.md

@@ -7,6 +7,7 @@ Not only is this a CLI tool, but it is also an importable package for converting
 + Example of input markdown: [./example/index.md](https://raw.githubusercontent.com/ksw2000/hackmd-to-html-cli/main/example/index.md)
 + Example of output html: [https://ksw2000.github.io/hackmd-to-html-cli/](https://ksw2000.github.io/hackmd-to-html-cli/)
 + Example of output html in dark mode: [https://ksw2000.github.io/hackmd-to-html-cli/index.dark.html](https://ksw2000.github.io/hackmd-to-html-cli/index.dark.html)
++ Example of converting in web: [https://ksw2000.github.io/hackmd-to-html-cli/webjs.html](https://ksw2000.github.io/hackmd-to-html-cli/webjs.html)
 
 ## Install