saber theme unit test #512

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Feature request

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What problem does this feature solve?

I need some tests to make sure all the styles in my theme are performed properly.

What does the proposed API look like?

hexo-theme-unit-test but for saber.

How should this be implemented in your opinion?

Bunch of .md files and a checklist.

Are you willing to work on this yourself?

Once if I know all the features that saber support.