Update target repository for Slack notifier

[mitruly]

Description Updated watcher and Slack link to layer5io/service-mesh-labs.

This PR fixes #1

Notes for Reviewers

Signed commits

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[welcome[bot]]

Yay, your first pull request! :thumbsup: A contributor will be by to give feedback soon. In the meantime, please review the Layer5 Community Welcome Guide and sure to join the community Slack. Be sure to double-check that you have signed your commits. Here are instructions for making signing an implicit activity while peforming a commit.

[welcome[bot]]

Thanks for your contribution to the Layer5 community! :tada:

[leecalcote]

Oh, no. @mitruly, another bug you might raise an issue to fix (the broken link to the image in .github/welcome folder).