Add workat.tech practice platform

Author: gcnit

README.md

@@ -39,6 +39,7 @@
 - [HackerEarth](https://www.hackerearth.com/challenges/)
 - [DailyCodingProblem](https://www.dailycodingproblem.com)
 - [UrionlineJudge](https://www.urionlinejudge.com.br/judge/en/login)
+- [Workattech DSA Interview Practice](https://workat.tech/problem-solving/practice?tags=dsa)
 
 
 ## Problem Solving Books: