Use case guides: support center and developer docs

[ethanpalm]

Documentation changes

Adds two new use case guides.

Closes https://linear.app/mintlify/issue/DOC-233/use-case-guides

---

For Reviewers

When reviewing documentation PRs, please consider:

✅ Technical accuracy

• Code examples work as written
• Commands and configurations are correct
• Links resolve to the right destinations
• Prerequisites and requirements are accurate

✅ Clarity and completeness

• Instructions are clear and easy to follow
• Steps are in logical order
• Nothing important is missing
• Examples help illustrate the concepts

✅ User experience

• A new user could follow these docs successfully
• Common gotchas or edge cases are addressed
• Error messages or troubleshooting guidance is helpful

---

Note

Adds two new use case guides and wires them into navigation and index; also updates the style/vocab.

• New guides: guides/developer-documentation.mdx and guides/support-center.mdx with prerequisites, setup steps, and maintenance best practices
• Navigation: Adds both guides to docs.json under Guides → Use cases; updates guides/index.mdx to link them
• Linting: Updates Vale vocabulary to accept SDK capitalization

^{Written by Cursor Bugbot for commit bc0433b. This will update automatically on new commits. Configure here.}