Update e2e testing doc with CI debugging info

docs/e2e-testing.md

@@ -436,3 +436,23 @@ this.submitButton.click();
 You can easily to use By(string) to locate a element which associated with testID in the app.
 
 It's recommended to define a `get` for each locator like above.
+
+## Debugging E2E Tests in CI
+If you have access to the AzureDevOps pipeline you'll be able to see test failures and debug crashes.
+Here are the artifacts that are produced during the build:
+- error screenshots of the app when a test failed
+- test run XML - this contains some information like the name of the wdio test that failed and the JS stack
+- tree dump outputs - you can compare these to the masters to see if there is a the difference responsible for the test failing. 
+- crash dumps of the e2e test app (ReactUWPTestApp)
+
+You can access these by going to the AzureDevOps run for your PR and clicking on the artifacts link:
+
+![Artifacts](img/e2e-artifacts.png)
+
+Then you can access crash dumps under the `ReactUWPTestAppTreeDump\CrashDumps` folder.
+![CrashDumps](img/e2e-crashdumps.png)
+
+You can get the symbols from the `appxsym` (just download it and rename it to `.zip`):
+![SymbolsPackage](img/e2e-syms.png)
+
+ The `ReactUWPTestAppTreeDump` folder will also contain any tree dump outputs that were produced that did not match the masters.

packages/E2ETest/README.md

@@ -1,3 +1,5 @@
 # E2ETest project
 
-This package is not published, and is just used to verify a standalone app
+This package is not published, and is just used to verify a standalone app
+
+For information on how to run and debug this project, see [e2e-testing](https://github.com/microsoft/react-native-windows/blob/master/docs/e2e-testing.md).