Make test template more explicit about helix logs (#48740)

* Make test template more explicit about helix logs

...since I got confused and did the wrong thing repeatedly.

* Add a note about signing in to AzDO

.github/ISSUE_TEMPLATE/50_test_failure.md

@@ -46,7 +46,8 @@ Provide the stack trace associated with the test failure, if applicable.
 
 <details>
 <!--
-Provide the (helix) logs associated with the test failure, if applicable.
+If this is a Helix test failure, include the text of the .log artifact from the failing test.
+Note that you have to be signed in to Azure DevOps to see the test artifacts.
 -->
 
 ```text