Rearanged scenario info

Why is this change being made?

When reading through this page it seemed odd to interject the Scenario info between describing how to write Tasks with additional Task tips. I think we should finish talking about Tasks and then address the optional Scenario information so I moved it under the last of the Task-oriented information.

I also removed the "Website" phrasing around the test script. This gave an air of copying the content from another source as we don't test websites we test our web app. In other words, the addition/use of this word seemed superfluous to our needs.

Author Checklist

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