DOCS-10186

[domalessi]

What does this PR do? What is the motivation?

https://datadoghq.atlassian.net/browse/DOCS-10186

• Removes Best Practices section from the Use Cases page
• Removes the Best Practices page entirely (and adds redirect links to Customize landing page)
• Moves the Validating Service Definitions page under the Customize parent
• Tweaks the Create Entries page slightly and adds a Further Reading link to Validating Service Definitions page

Merge instructions

Merge readiness:

• Ready for merge

Merge queue is enabled in this repo. To have it automatically merged after it receives the required reviews, create the PR (from a branch that follows the <yourname>/description naming convention) and then add the following PR comment:

/merge

Additional notes

[github-actions]

Preview links (active after the build_preview check completes)

Removed or renamed files (these should redirect)

• https://docs-staging.datadoghq.com/domalessi/docs-10186/software_catalog/use_cases/best_practices

Renamed files

• https://docs-staging.datadoghq.com/domalessi/docs-10186/software_catalog/customize/validating_service_definition

Modified Files

• https://docs-staging.datadoghq.com/domalessi/docs-10186/software_catalog/customize/
• https://docs-staging.datadoghq.com/domalessi/docs-10186/software_catalog/customize/create_entries
• https://docs-staging.datadoghq.com/domalessi/docs-10186/software_catalog/use_cases/