docs: update /test readme (#5821)

Updating the readme located at `/test`

test/README.md

@@ -1,9 +1,14 @@
-# VSCode Tests
+<!-- Start Positron -->
+<!-- If you are seeking the original Vscode README go here: https://github.com/microsoft/vscode/tree/main/test -->
+
+# Positron Tests
 
 ## Contents
 
-This folder contains the various test runners for VSCode. Please refer to the documentation within for how to run them:
+This folder contains the various test runners for Positron. Please refer to the documentation within for how to run them:
 
 * `unit`: our suite of unit tests ([README](unit/README.md))
 * `integration`: our suite of API tests ([README](integration/browser/README.md))
-* `smoke`: our suite of automated UI tests ([README](smoke/README.md))
+* `e2e`: our suite of Playwright end-to-end tests ([README](e2e/README.md))
+
+<!-- End Positron -->