Update index.md

Author: Mostafa Kamal

javascript-developer/extra/semver/index.md

@@ -19,6 +19,7 @@
 * [devhints](https://devhints.io/semver)
 * [bytearcher](https://bytearcher.com/goodies/semantic-versioning-cheatsheet/)
 * [npmjs](https://docs.npmjs.com/misc/semver)
+* * https://semver.npmjs.com/
 
 # blog