lint-files test fails on Windows

[jeffmcaffer]

What is the current behavior?

8 of the relative URLs must start with "/" tests in tests/content/lint-files.js fail because of some windows pathing issues. Here is one example.

 FAIL  tests/content/lint-files.js (217.925 s)
  ● lint-files › in "content\actions\hosting-your-own-runners\monitoring-and-troubleshooting-self-hosted-runners.md" › relative URLs must start with "/"

    Custom message:
      Found unexpected relative article links:
      - [962]: Starting
      - [962]: Started
      - [962]: Started
      - [962]: √
      - [962]: 2020-02-11
      - [962]: 2020-02-11
      - [962]: 2020-02-11

    expect(received).toBe(expected) // Object.is equality

    Expected: 0
    Received: 7

      178 |
      179 |         const errorMessage = formatLinkError(relativeArticleLinkErrorText, matches)
    > 180 |         expect(matches.length, errorMessage).toBe(0)
          |                                              ^
      181 |       })
      182 |
      183 |       test('URLs must not contain a hard-coded language code', async () => {

      at Object.<anonymous> (tests/content/lint-files.js:180:46)

What changes are you suggesting?

The problem is with the relative path computations near the beginning of the test. These should be wrapped with a slash call.

cc: @github/docs-engineering , @chiedo