feat(docs): add SoftwareApplication JSON-LD to the landing page

[myromartsin]

Summary

The landing page head carries a JSON-LD block typed as SoftwareApplication and SoftwareSourceCode, declaring the library name, description, category, license, repository, and package links for search engines and AI crawlers.

Motivation

Structured data feeds rich results and AI Overviews retrieval.

Conformance impact

None.

Checklist

• Tests added or updated (or a rationale for why none)
• pnpm test, pnpm lint, pnpm format pass locally
• Docs reflect the change (per CONTRIBUTING.md)
• Commit message follows the project convention

[github-actions]

Site preview: https://3fd055bc.telixon-landing.pages.dev

[codspeed-hq]

Merging this PR will not alter performance

✅ 39 untouched benchmarks

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_{Comparing feat/landing-json-ld (5fdeefe) with main (2b9624d)}