Add missing TestDox on exercices (issue #1021)

[resu-xuniL]

• Added missing TestDox on HouseTest
• Added missing TestDox on KillerSudokuHelperTest
• Added missing TestDox on MicroBlogTest
• Added missing TestDox on StrainTest
• Added missing TestDox on SublistTest
• Added github handle

(Tell me if I shall drop the last commit)

[no important files changed]

Ref: #1021

[github-actions]

This PR touches files which potentially affect the outcome of the tests of an exercise. This will cause all students' solutions to affected exercises to be re-tested.

If this PR does not affect the result of the test (or, for example, adds an edge case that is not worth rerunning all tests for), please add the following to the merge-commit message which will stops student's tests from re-running. Please copy-paste to avoid typos.

[no important files changed]

For more information, refer to the documentation. If you are unsure whether to add the message or not, please ping @exercism/maintainers-admin in a comment. Thank you!

[mk-mxp]

You are welcome to add your handle to all exercises you did something on.

Thanks a lot for taking care of this!

[resu-xuniL]

You're welcome