Manual vs Scored documentation

[joebowbeer]

I created an issue to document the --unscored flag: #1281

In addition, I think some documentation changes are needed regarding Manual vs Scored tests.

There is a lot of confusion about this, and the clearest explanation exists only in the discussions:

• There are automated tests for some items that are marked as "(Manual)" #906 (comment)
• Some tests that are "Manual" as per the text field are not marked "type: manual" #772 (comment)
• Need help understanding WARN state and scoring mechanism #595 (reply in thread)

The references to Manual in the documentation are ambiguous because they can refer either to a type meaning the test is not automated, or they can refer to some text in the test description, indicating that the test is not scored, even though it may or may not be automated (executable).

There are also a few tests with (Automated) in their description that are not scored.

[mozillazg]

@joebowbeer You are right, we should update documents to cover these questions. PR is welcome.