Complete v16.0.0: Hermes Agent support + multi-platform rebrand (#26)

Learnings applied from alirezarezvani/claude-skills: native SKILL.md agents
(Hermes, Vibe) install the files directly — no conversion — so support is a
sync script, not regenerated copies.

- scripts/sync-hermes-skills.py: stdlib installer that places skills/ into
  ~/.hermes/skills/ (copy or --link symlink, --flat, --dry-run). Hermes reads
  the same open SKILL.md standard and auto-discovers by description.
- README rebrand: title, tagline, intro, and a "works with" platforms badge now
  cover Claude, ChatGPT, Gemini, and Hermes. Works-With table splits native
  SKILL.md agents (Claude Code, Hermes) from paste-in chat LLMs. Repo name,
  marketplace ID, and install commands intentionally unchanged.
- Version bump to v16.0.0 (Multi-Platform). Note: v15.0.0 was already published
  (Skill Playground), so this release is v16.0.0; the changelog now also records
  v15.0.0 in its history. Updated README badge/What's-New, CHANGELOG, SECURITY,
  and playground tagline/meta.


Claude-Session: https://claude.ai/code/session_016JWn5jRD5tcEFKrubjQ6Px

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

SECURITY.md

@@ -10,9 +10,9 @@ That said, security matters here in two specific ways: **skill file safety** and
 
 | Version | Supported |
 |---|---|
-| v14.x (latest) | ✅ Active |
-| v12.x – v13.x | ✅ Security fixes only |
-| < v12.0.0 | ❌ No longer supported |
+| v16.x (latest) | ✅ Active |
+| v14.x – v15.x | ✅ Security fixes only |
+| < v14.0.0 | ❌ No longer supported |
 
 Because skills are plain markdown, "support" means we review and correct any reported
 safety issue (prompt injection, unsafe instructions) in the listed versions.