(MAINT) Decompose TOC

[michaeltlombardi]

PR Summary

Prior to this change, the TOC for the documentation was contained in a single top-level configuration file, which was difficult to parse, reason about, and maintain.

This change:

• Decomposes the TOC into smaller files collocated with the documentation for a smaller scope of management, easier maintenance, and readability.
• Updates the TOC to add missing entries for documentation.

PR Checklist

• Descriptive Title: This PR's title is a synopsis of the changes it proposes.
• Summary: This PR's summary describes the scope and intent of the change.
• Contributor's Guide: I have read the contributors guide.
• Style: This PR adheres to the style guide.

[learn-build-service-prod]

Learn Build status updates of commit 37927ba:

✅ Validation status: passed

File	Status	Preview URL	Details
dsc/docs-conceptual/dsc-3.0/concepts/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/cli/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/resources/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/schemas/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/tools/toc.yaml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/toc.yml	✅Succeeded	View (dsc-3.0)

For more details, please refer to the build report.

[learn-build-service-prod]

Learn Build status updates of commit 812fe91:

✅ Validation status: passed

File	Status	Preview URL	Details
dsc/docs-conceptual/dsc-3.0/concepts/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/cli/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/resources/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/schemas/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/toc.yml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/reference/tools/toc.yaml	✅Succeeded
dsc/docs-conceptual/dsc-3.0/toc.yml	✅Succeeded	View (dsc-3.0)

For more details, please refer to the build report.