Add: Headless Testing (#2071)

* Add description and example usage cases

* Update content/roadmaps/113-qa/content/111-qa-headless-testing/readme.md

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/113-qa/content/111-qa-headless-testing/readme.md

@@ -1 +1,9 @@
-# Qa headless testing
+# Headless Testing
+
+Headless testing is when end-to-end tests are performed without loading the browser's user interface. Since the browser operates as a typical browser would but does not make use of the user interface, it is considered highly suitable for automated testing.
+
+A few example cases where one may use headless browser testing include:
+
+- Automating HTML event responses, such as form submission, keyboard events, mouse-clicking, etc.
+- Web scraping
+- Generating screenshots of webpages