Improved visibility of AI tools and other tweeks

[bdenham]

Purpose of this pull request

This pull request (PR) makes AI tools and storefront project guidance easier to find in the Developers sidebar. It aligns the Getting started overview with the revised navigation and restores the intended spacing between headings and Steps components without changing page URLs.

• Promote AI tools and Boilerplate to main Developers sections. Keep AI tools expanded by default and collapse Architecture by default.
• Keep Luma Bridge under Configuration only, and group the licensing topics in an expanded Licensing folder under Drop-ins.
• Limit Getting started to Overview, Prerequisites, Backend options, and Create a storefront. Update the overview's setup path, follow-up links, and How-tos navigation guidance.
• Exclude Steps components from the ordinary-list spacing rule, restoring their existing 1rem heading gap while preserving ordinary-list spacing.

Validation:

• pnpm build:prod-fast - passed; reported All internal links are valid.
• git diff --check origin/release...HEAD - passed.
• Focused sidebar and overview assertions - passed.
• Playwright checks at 1280px and 390px viewport widths - passed; heading-to-Steps gap is 16px and ordinary-list spacing is unchanged.

Associated JIRA ticket

No JIRA ticket was identified in the branch name.

Staging preview

No staging preview is available yet.

Affected pages

• https://experienceleague.adobe.com/en/tools/commerce-storefront/get-started/
• https://experienceleague.adobe.com/en/tools/commerce-storefront/ai/
• https://experienceleague.adobe.com/en/tools/commerce-storefront/boilerplate/
• https://experienceleague.adobe.com/en/tools/commerce-storefront/licensing/
• https://experienceleague.adobe.com/en/tools/commerce-storefront/licensing/license-agreement/
• https://experienceleague.adobe.com/en/tools/commerce-storefront/setup/discovery/luma-bridge/
• https://experienceleague.adobe.com/en/tools/commerce-storefront/how-tos/add-block-to-page/

Sidebar changes apply throughout the documentation site. The spacing fix applies to headings followed directly by Steps components.

Links to source code

No associated source code PRs.

What's New highlights

Not applicable; documentation navigation and presentation updates only.