[DOCS] Update "Managing detection alerts" topic

[jmikell821]

Topic: https://www.elastic.co/guide/en/security/current/alerts-ui-manage.html

Note: Remove the gerund from the title and change Managing > Manage.

Let's try to enhance this topic a bit by pointing out some features that will enable users to filter/manage alerts, such as:

• Ability to filter indicator match rules ([CTI] Filters alerts table by presence of threat (elastic/security-team#907) kibana#96096)
• Expand the Alert details button > next to the check box to display the flyout panel, which now includes the new Threat intel tab ([CTI] Adds Threat Intel Tab to Alert Summary Flyout kibana#97185)
• Customize rows and column renderers (this is mentioned briefly, but I think we can expand on this a bit; it's very vague and has no illustrations or anything)

Note: This legend provides the customization options:

Other ways to filter:

• Date/time
• Index field Stack by drop-down menu
  

It might be beneficial to add a section at the top that says "Sort and filter alerts".

[jmikell821]

Merged #666.