[WIP] Update uptime sources and build alias

[EamonnTP]

This PR updates the source and doc build alias for the Uptime Monitoring Guide.

The Uptime monitoring content is in the process of being moved from the Kibana repo to the Observability docs repo.

[gtback]

I converted this to a Draft PR so it's less likely to get accidentally merged. I think we'll need to set up redirects from the old URL to the new one. Assuming the pages themselves aren't changing, a wildcard redirect should be fine.

[EamonnTP]

Thanks @gtback

[bmorelli25]

I converted this to a Draft PR so it's less likely to get accidentally merged. I think we'll need to set up redirects from the old URL to the new one. Assuming the pages themselves aren't changing, a wildcard redirect should be fine.

There shouldn't be any URL changes as a result of this PR. Only the backend content is moving

[gtback]

🤦 Good call @bmorelli25 . I saw the "index" attribute changed and my mind read that as a URL.

[bmorelli25]

Haha, no worries. I did a double-take as well when I saw that. prefix and index are easily confused!

[bmorelli25]

This LGTM once docs ci passes.

[EamonnTP]

@elasticmachine, run elasticsearch-ci/docs

[bmorelli25]

The diff looks clean to me. I think you've pulled it off!