Clarify config management notes for Drupal for WebOps Workflow

[joan-ing]

Expected behavior

• Version specific information is provided for the the config management notes for Drupal in Use the Pantheon WebOps Workflow

Actual behavior

• The config management notes for Use the Pantheon WebOps Workflow refer to using update hooks or features. It is unclear whether we were advocating using this over config sync (import/export) for D9 / D8 sites. The docs don't mention a version, and I'm guessing we'd want them to describe the process for the latest version anyway.

Suggested Resolution

• We should clarify with version-specific information and most likely describe the process for the latest version.
• Update information on automating Drupal site updates with a deployment module, if needed for D9

Additional information

• Slack thread

[EdwardAngert]

@wordsmither this might be relevant to the Drupal cross-linking adventure you're on

[wordsmither]

It does not appear to be related to the cross-linking project. Unassigning myself for now.

[wordsmither]

waiting on https://getpantheon.atlassian.net/browse/CMS-755