Guide: JSON formatting and validation best practices

[anurag629]

Context

Part of the SEO growth initiative (#18): Phase 2: Coverage engine (guides and internal linking).
Captures informational JSON queries and cross-links the JSON Formatter.

What to do

• Write a genuinely useful, original guide (examples, screenshots, or a table) that answers the query in the first two sentences.
• Use clear H2/H3 that match sub-questions, short paragraphs, and lists.
• Link to the JSON Formatter tool and to related guides.

Where

New guide entry via the guides content system (depends on #GUIDES). Content lives in the guides registry/MDX established there.

Acceptance criteria

• Guide published, answers the query up top, and links to the relevant tool
• npm run lint && npm run test && npm run build passes

Notes

Branch off develop (feat/*, docs/*, chore/*), open a PR into develop, and squash-merge. See CONTRIBUTING.md.
Depends on the guides content system.