Add WebDB to database GUI

I'm his creator so maybe I'm a little bit too biased to be completly objective.
Anyway, this is a very great tool to manage/design database, that's why I thought It's a great place to show him

README.md

@@ -93,7 +93,11 @@ Feel free to take a look. You might learn new things. They have been designed to
 #### NoSQL
 
 - [Redis](databases/redis.sh)
-  </details>
+
+#### GUI
+
+- [WebDB](https://webdb.app)
+</details>
 
 ### 🔧 Tools