profiling: introduce self-managed beta for 8.12

[inge4pres]

Reason for this PR

Addresses elastic/prodfiler/issues/4139.

Details

• Create the documentation to install and run the Universal Profiling backend on various platforms: ECE, K8s, Linux.
• Document operational practices to monitor and scale the backend components
• Add a troubleshooting section to overcome known issues

To be refined

The operational and troubleshooting sections are still empty, working on it in the next days

[github-actions]

A documentation preview will be available soon:

• 📚 HTML diff
• 📙 Observability Guide

[mergify]

This pull request does not have a backport label. Could you fix it @inge4pres? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-/d./d is the label to automatically backport to the /d./d branch. /d is the digit
  NOTE: backport-skip has been added to this pull request.

[inge4pres]

@iogbole the preview link

https://observability-docs_bk_3379.docs-preview.app.elstc.co/guide/en/observability/master/universal-profiling.html

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 4b4c6e0
• Documentation preview
  • 📚 HTML diff
  • 📙 Preview

History

• 💚 Build #104 succeeded 742a6d4ad31d42637cedba646a8cc0061a795fbe
• 💔 Build #103 failed 742a6d4ad31d42637cedba646a8cc0061a795fbe
• 💚 Build #101 succeeded 742a6d4ad31d42637cedba646a8cc0061a795fbe

cc @inge4pres

[mdbirnstiehl]

I made some changes just for consistency and wording, and I think I have the document organization in a good place now, but please take a look and let me know if you have any questions or issues.

[bmorelli25]

Okay. Last review from me!

[bmorelli25]

Is this reflected on https://www.elastic.co/subscriptions? For legal reasons, we don't name the license level required in the documentation and instead link to the source of truth (the subscriptions page). Here's an example from the SLO docs:

To create and manage SLOs, you need an {subscriptions}[appropriate license].

Can we do the same here? Will UP be added to the subscriptions page when 8.12 releaes?

[inge4pres]

I summon @iogbole on this one as I have no clue about the other page.
I am only aware that for on-prem we need Enterprise... we have a check in the code to enforce that.

@bmorelli25 can suggest what should be the appropriate format here?
I guess

Suggested change

	IMPORTANT: Running Universal Profiling on self hosted infrastructure requires an Elastic **Enterprise license**.
	IMPORTANT: Running Universal Profiling on self hosted infrastructure requires an Elastic **{subscriptions}[Enterprise license]**.

[mdbirnstiehl]

I've moved this line to the top of the page here to be consistent with the rest of the obs docs.

If we are able to get the Profiling subscription info on the subscriptions page, we wouldn't want to explicitly say what kind of license users need in the docs. With this in mind, I phrased it this way:

IMPORTANT: To run Universal Profiling on self-hosted Elastic stack, you need an {subscriptions}[appropriate license].

If we aren't able to get the info on the subscriptions page, maybe we can rephrase to be specific in this instance.

[mdbirnstiehl]

I think we can merge this now, I'll make a note to come back and check on the subscription statement when we get closer to the 8.13 release.