Hyperlink format is incorrect on All-in-One doc

[marhabac33]

Hyperlink format is HTML therefore it shows up as plain text instead of hyperlink on https://open-horizon.github.io/docs/mgmt-hub/docs/index.html

Note: https://github.com/open-horizon/open-horizon.github.io/pull/339 was delivered to fix the format over in https://github.com/open-horizon/open-horizon.github.io/ . However the approach is wrong because GH action will overwrite the fix next time the page is updated in the devops repo

[marhabac33]

@johnwalicki please assign me the issue. I will have the PR up.

[johnwalicki]

Thanks @marhabac33