Updated the sandbox links to Templates, Workflows, and Hardware Data

[saltyautomation]

Updated documentation links that were dead. First commit so please take it easy on me. Still learning the ropes here. I am also not sure if the workflows link is the right one as there are two workflow doc links on the tinkerbell site. Happy to change it if needed.

The old links no longer worked.

Fixes #149

How Has This Been Tested?

I clicked the links to the new documentation.

How are existing users impacted? What migration steps/scripts do we need?

Checklist:

I have:

• [ x] updated the documentation and/or roadmap (if required)
• [ ] added unit or e2e tests
• [ ] provided instructions on how to upgrade

[chrisdoherty4]

@saltyautomation Thanks for the update. The DCO needs signing off with git commit --amend --signoff --no-edit.

[chrisdoherty4]

The documentation has since moved on and no longer references these links.