Update jest doc URL

[scottyzen]

What kind of change does this PR introduce? (check at least one)

• [ ] Bugfix
• [ ] Feature
• [ ] Code style update
• [ ] Refactor
• [x] Docs
• [ ] Underlying tools
• [ ] Other, please describe:

Does this PR introduce a breaking change? (check one)

• [ ] Yes
• [x] No

Other information: Fix the broken link first found here: https://cli.vuejs.org/core-plugins/unit-jest.html#injected-commands Update URL from https://facebook.github.io/jest/docs/en/cli.html to https://jestjs.io/docs/cli