Prebuilt detection rules: new UI for installing and upgrading

[joepeeples]

Features/issues covered:

• Resolves [DOCS] Document the new UI for installing and upgrading prebuilt detection rules #3496.
• Also resolves [Detection rules] Prebuilt rules tags documentation #3525, which I included when I realized it depended on the rest of this PR.

Previews:

• Manage detection rules
• Install Elastic prebuilt rules — New page, breaks out existing prebuilt rule sections from the Manage detection rules page, revises those and adds new section for updating rules. Also adds a new section for Prebuilt rule tags (to address #3525).
• A few small, isolated name changes on various pages (also spot check these for to make sure frontmatter isn't rendered):
  • en/security/master/alerts-ui-monitor.html
  • en/security/master/d4c-get-started.html
  • en/security/master/machine-learning.html

[github-actions]

Documentation previews:

• ✨ HTML diff
• 📙 Elastic Security Guide

[joepeeples]

@elasticmachine run elasticsearch-ci/docs

[banderror]

Fantastic documentation update @joepeeples! 🎉

I did leave a few comments though, some of them are minor.

cc @xcrzx @jpdjere in case you'd like to take a look as well.

[nastasha-solomon]

Good idea breaking out the instructions for working with prebuilt rules. I left a handful of suggestions - hopefully they're helpful!

[approksiu]

Thanks Joe! New docs look great!
https://security-docs_3552.docs-preview.app.elstc.co/guide/en/security/master/rules-ui-management.html#enable-detection-rules - I suggest removing this section with the video, it is outdated. cc @joepeeples

[jmikell821]

I wasn't too nitpicky with comments in the interest of time, but this was a really great write-up, @joepeeples! I see Ksenia and Georgii left some feedback too. Once all that's incorporated, this will be good to go!

[banderror]

Thank you @joepeeples for addressing all the comments! Looks great!