Please update stale hyperlink for Googletest primer

[noonfom]

The Googletest primer has been moved to the top-level docs directory, so the hyperlink on this page is stale.

Page link

https://os.mbed.com/docs/mbed-os/v6.6/debug-test/unit-testing.html

Expected to find...

documentation for Google Test

Found

documentation for Google Test

[ciarmcom]

@noonfom This issue has an incomplete or old issue template.For future reference please use an up to date clone of the repository before raising issues. Many thanks.

[ciarmcom]

Thank you for raising this detailed GitHub issue. I am now notifying our internal issue triagers.
Internal Jira reference: https://jira.arm.com/browse/IOTOSM-3314

[0xc0170]

@noonfom Can you send a pull request fixing this url?

[noonfom]

@0xc0170 Sure. I opened #1402 to resolve this issue.

[ChrisGooch-Arm]

The above fix was accepted and merged and published as of v6.8:

https://os.mbed.com/docs/mbed-os/v6.8/debug-test/unit-testing.html