docs: add ai-search configuration documentation

[devin-ai-integration]

docs: add ai-search configuration documentation

Summary

Adds documentation for the new ai-search configuration options in docs.yml that were introduced in PR #9788 and initially documented in PR #1302.

Changes:

1. Added new "AI search configuration" section to the docs.yml reference page (what-is-docs-yml.mdx) with concise ParamField descriptions for location and datasources fields
2. Updated the Ask Fern getting started page (what-is-ask-fern.mdx) to clarify that Ask Fern can be configured via both the Dashboard and docs.yml (not one or the other)

The documentation now provides a comprehensive reference for the ai-search configuration block while keeping ParamField descriptions concise, with auxiliary information in a Note callout that links to the detailed locations-and-datasources page.

Review & Testing Checklist for Human

This is a yellow risk PR (documentation only, but accuracy is important).

• Verify internal links work correctly: Test that the link from what-is-ask-fern.mdx to #ai-search-configuration navigates properly to the new section, and confirm the link to /learn/ask-fern/configuration/locations-and-datasources in the Note works
• Test the actual configuration: Create a test docs.yml with the ai-search block using the documented options (location: [docs, slack, discord] and datasources) to verify the syntax and options are accurate
• Check rendering: Verify the ParamField components and Note callout render correctly with proper formatting

Test Plan

1. Deploy to preview and navigate to both updated pages
2. Click the link from what-is-ask-fern page to verify it jumps to the new AI search configuration section
3. Create a test docs.yml with the ai-search configuration and run fern generate --docs --preview to verify it works

Notes

• Placed the new section between Analytics and Dynamic snippets configuration for logical flow
• Simplified ParamField descriptions per feedback to show only essential information (string options)
• Moved auxiliary details and the "Learn more" link to the Note callout
• Session: https://app.devin.ai/sessions/0a56e69f7da14a4194f071f151d3f094
• Requested by: [email protected] (@Ryan-Amirthan)

[devin-ai-integration]

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[github-actions]

🌿 Preview your docs: https://fern-preview-f81f54df-4aa6-4274-8856-89de4589ce0f.docs.buildwithfern.com/learn

[github-actions]

🌿 Preview your docs: https://fern-preview-bab6260f-0e70-4373-a3b4-1449dbe9f897.docs.buildwithfern.com/learn