feat(docs-migration): second iteration of docs migration (#5056)

<!-- Describe the problem and your solution --> 
Migrates:
accelo ✅
amazon ❌ - api route for the proxy is wrong
apollo
asana
attio
box
calendly
clickup
confluence
discord
dropbox
freshdesk
github-app
github-app-oauth
google-ads
google-analytics
google-docs
instagram
intercom
linear
linkedin
microsoft
microsoft-teams
one-drive
outlook
pipedrive
quickbooks
salesforce-sandbox
sharepoint-online
stripe
twitter-v2
whatsapp-business
xero
youtube
zendesk
zoom
zoho-crm

<!-- Issue ticket number and link (if applicable) -->

<!-- Testing instructions (skip if just adding/editing providers) -->

<!-- Summary by @propel-code-bot -->

---

**Docs Migration Second Wave: Standardize Integration Guides in New
Hub**

This PR advances the documentation migration by moving dozens of
connector guides from the legacy `docs/integrations/all/` section into
the newer `docs/api-integrations/` hierarchy. Each guide now follows the
refreshed template with updated front matter, consistent setup
instructions, and current OAuth walkthroughs to align with the modern
documentation framework.

Supporting assets and author guidance were also refreshed so the new
structure is discoverable and maintainable across the product.
Navigation manifests, Connect UI references, and `managed-manifest.json`
were updated, while `.claude/skills/creating-integration-docs/SKILL.md`
and `AGENTS.md` now describe the revised workflow and contributor
expectations. Broken links and outdated assets were cleaned up, though
Amazon integration docs remain partially blocked pending a proxy fix and
future redirect work.

<details>
<summary><strong>Key Changes</strong></summary>

• Migrated 40+ connector guides from `docs/integrations/all/` to the new
`docs/api-integrations/` hub with standardized templates and updated
OAuth content
• Updated navigation manifests, Connect UI references, and
`managed-manifest.json` to point to the new documentation paths
• Refreshed contributor guidance in
`.claude/skills/creating-integration-docs/SKILL.md` and `AGENTS.md`, and
fixed image assets and broken links uncovered during migration
• Documented outstanding follow-up for Amazon integration docs and
pending redirects from legacy URLs

</details>

<details>
<summary><strong>Affected Areas</strong></summary>

• docs/api-integrations/
• docs/integrations/all/
• managed-manifest.json
• Connect UI documentation references
• .claude/skills/creating-integration-docs/SKILL.md
• AGENTS.md

</details>

---
*This summary was automatically generated by @propel-code-bot*

Author: khaliqgant

.claude/agents/nango-docs-migrator.md

@@ -0,0 +1,7 @@
+{
+    "permissions": {
+        "allow": ["Skill(agent-builder-skill)", "Skill(creating-skills-skill)", "WebFetch(domain:github.com)"],
+        "deny": [],
+        "ask": []
+    }
+}