[REQUEST][AutoOps] Various doc updates

[alaudazzi]

Description

• Replace the word endpoint with the word connector as we no longer use endpoint in the UI.
  [AutoOps] Replace endpoint with connector #786
  We should replace in all places except in:
  • REST Endpoint Integration Guide
  • Webhook integration
    • section 3 - endpoint_type
    • URL: This is the endpoint to which HTTP POST requests will be sent when events occur.
• Add a new page on Email connector, as per this gdoc [AutoOps] Add Email connector #574
• Update the AutoOps regions page with AWS | ap-southeast-1 | Singapore [AutoOps] Update the supported AutoOps regions #572

Resources

Slack thread with PM and docs

Which documentation set does this change impact?

Elastic On-Prem and Cloud (all)

Feature differences

N/A

What release is this request related to?

9.0

Collaboration model

The documentation team

Point of contact.

@alaudazzi
@arnonst

CC @eedugon

[alaudazzi]

Relates to #303