docs: improve SEO — homepage title and meta descriptions for 10 pages

[ekline]

Context

This PR addresses SEO issues identified by auditing the Fastn documentation against the company's keyword strategy derived from fastn.ai marketing pages.

Keyword map

Primary keywords (from marketing site):

• "embedded integration platform"
• "MCP platform for enterprise integrations"
• "adaptive context layer for AI agents"
• "unified context layer"
• "AI agent integrations"

Secondary keywords:

• "multi-tenant MCP server"
• "SaaS integration platform"
• "AI workflow automation"
• "connector library for AI agents"

Audience terms: SaaS developers, AI agent builders, platform engineers

Top 3 findings

Rank	Priority	Page	Issue	Proposed fix
1	High	README.md	Homepage H1 "About Fastn" is generic with no keywords; meta description is only 52 chars, missing primary search terms	Fixed in this PR
2	High	9 section READMEs	Section landing pages have no frontmatter descriptions — no meta descriptions for search engines	Fixed in this PR
3	Medium	flows/quick-start-guide.md	Title "Quick Start Guide" is generic — no product name or domain keyword	Follow-up work

What this PR fixes

Fix 1: Homepage title and meta description

• H1: About Fastn → Fastn: embedded integration platform for AI agents
• Meta description: 52 chars → ~155 chars with primary keywords
• SUMMARY.md: Updated nav entry to match

Fix 2: Meta descriptions for 9 section landing pages

Added description frontmatter to pages that had none:

Page	Description added
flows/.../connecting-apps/README.md	Connect your Fastn flows to external apps, APIs, and databases using prebuilt or custom connectors with managed authentication.
flows/.../data-and-storage/README.md	Store and manage data in your Fastn flows using the built-in database or external databases like PostgreSQL and Redshift.
flows/tutorials/data-migrations/README.md	Automate data migrations between Google Drive, AWS Redshift, and Google Cloud Storage using Fastn flows and widgets.
flows/tutorials/flow-customization.../README.md	Customize Fastn flow behavior for authentication, error handling, multi-app connections, and pagination.
flows/tutorials/understanding-flow-types/README.md	Learn about Fastn flow types including activation, selection, and configuration flows for embedded widgets.
.../deployment/README.md	Manage how your Fastn flows, connectors, and widgets move between environments using releases and pipelines.
resources/library/README.md	Tutorials, glossary, and FAQs for Fastn's embedded integration platform, AI agent builder, and MCP server gateway.
resources/library/faqs.md	Answers to common questions about Fastn flows, debugging, data syncs, connector filtering, and integration best practices.
resources/library/glossary.md	Definitions of key Fastn terms including connectors, flows, tenants, MCP, UCL, workspaces, and AI agent components.

Remaining items

• Tutorial: Build your first flow #3 (Medium): Add product name and domain keywords to generic page titles like "Quick Start Guide"

How to verify

1. Check that frontmatter renders correctly in GitBook preview
2. Confirm the SUMMARY.md nav entry displays the updated title in the sidebar
3. Verify meta descriptions appear in page source for each updated page