Add docs for Fleet Desktop and integrations

[noahtalerman]

Issue #5017

• Add "Fleet Desktop" section to "Adding hosts" doc page.
  • Prioritize instructions to install Fleet Desktop
  • Include links to Self-service and Scope transparency features, Linux versions supported, and remaining work to bring Fleet desktop out of beta
• Add instructions to add Jira or Zendesk integration to "Vulnerability automations" section in the "Automations" doc page.

[noahtalerman]

@DominusKelvin I added you as a reviewer.

Do you think these updates are placed in the correct location of the docs? Could they be shortened / simplified?

[noahtalerman]

@Desmi-Dizney I added you as a reviewer.

Can you please take an editor pass on these updates?

[noahtalerman]

@tgauda I added you as a reviewer.

Can you please check to see if these doc updates address most of the questions you've been hearing from customers about Fleet Desktop and Integrations?

[Desmi-Dizney]

@Desmi-Dizney I added you as a reviewer.

Can you please take an editor pass on these updates?

@noahtalerman, you've got it!

[tgauda]

👍🏾

Requested changes were addressed.

[noahtalerman]

Hey @tgauda when you get the chance, can you please approve this PR again?

I updated the PR which automatically removed your review. Apologies for the extra ping.

[noahtalerman]

@lucasmrod FYI in these doc updates, I link to your following GitHub comment which outlines the current Linux support: #5684 (comment)

This way, the docs aren't duplicating what you already documented in that comment.

[Desmi-Dizney]

Editor pass: No edits required