chore: added basic jest testing support

also added an example test for the counter in the components.tsx file to demonstrate functionality of testing configuration. installed all dependencies for testing using --save-dev to make sure they are stored as dev dependencies

ref: N25B-212

test/setupTests.ts

@@ -0,0 +1,2 @@
+// Adds jest-dom matchers for React testing library
+import '@testing-library/jest-dom';