chore: GitHub issue template untuk template request + feature request

[ajianaz]

Sumber: riset user-needs — belum ada channel resmi user request template/fitur.

Desain proposal:

• .github/ISSUE_TEMPLATE/template_request.yml: form (nama template, use case, ukuran, referensi visual/link, konten sample).
• .github/ISSUE_TEMPLATE/feature_request.yml: form (problem, proposed solution, alternatives).
• .github/ISSUE_TEMPLATE/config.yml dengan contact links (Discord).

Acceptance:

• /issue/new?template=... menampilkan form; label otomatis (template-request, enhancement).

Effort: S. Prioritas #7 (cheapest user research).