docs: update README to reflect ~150 issues of new features (#173)

* feat: add GitHub issue templates

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* docs: update README to reflect features added since issue #19

- Remove outdated early-development warning
- Add new feature rows: nDPI security detection, file extraction,
  session reconstruction, geolocation & device classification,
  MAC manufacturer lookup
- Update network visualization entry (React Flow + ELK, no longer 3D)
- Update conversation tracking (column picker, bulk PCAP, payload filter)
- Update story mode (LLM Q&A chat, custom context)
- Expand export options (PDF, per-conversation PCAP, bulk PCAP, CSV)
- Expand usage workflow from 7 to 9 steps
- Add PCAPNG to supported file formats
- Update tech stack: reagraph → React Flow + ELK, pcap4j → tshark + nDPI v5

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix: address review comments on sub-issue template

- Add 'sub-issue' default label for consistency with other templates
- Remove unnecessary backslash escaping from placeholder brackets

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Merge pull request #1 from NotYuSheng/release/v1.0.0

Release/v1.0.0