Add resources for regression testing (#8482)

The QA roadmap does not have any resources for Regression Testing. I have added three resources for it.

src/data/roadmaps/qa/content/regression-testing@XCeXiKvBblmDArfbWjDvw.md

@@ -1,3 +1,9 @@
 # Regression Testing
 
-Regression Testing is a type of software testing to confirm that a recent program or code change has not adversely affected existing features. Regression testing is a black box testing technique. Test cases are re-executed to check the previous functionality of the application is working fine and that the new changes have not produced any bugs.
+Regression Testing is a type of software testing to confirm that a recent program or code change has not adversely affected existing features. Regression testing is a black box testing technique. Test cases are re-executed to check the previous functionality of the application is working fine and that the new changes have not produced any bugs.
+
+Visit the following resources to learn more:
+
+- [@article@What is Regression Testing?](https://www.guru99.com/regression-testing.html)
+- [@article@What is Regression Testing? Definition, Tools and Examples](https://katalon.com/resources-center/blog/regression-testing)
+- [@video@What is Regression Testing? A Software Testing FAQ - Why? How? When?](https://www.youtube.com/watch?v=xmQuLTarGI4)