docs: expand scope and add comprehensive documentation

Create README.md and enhance AGENTS.md to position this as an
extensible framework for any Opencode skills and agents, not just
PARA/task management. Includes installation, development workflow,
code style guidelines, and Nix flake integration patterns.

skill/knowledge-management/SKILL.md

@@ -0,0 +1,60 @@
+---
+name: knowledge-management
+description: "Knowledge base and note management with Anytype. Use when: (1) saving information for later, (2) organizing notes and references, (3) finding past notes, (4) building knowledge connections, (5) managing documentation. Triggers: save this, note, remember, knowledge base, where did I put, find my notes on, documentation."
+compatibility: opencode
+---
+
+# Knowledge Management
+
+Note capture and knowledge organization using Anytype as the backend.
+
+## Status: Stub
+
+This skill is a placeholder for future development. Core functionality to be added:
+
+## Planned Features
+
+### Quick Note Capture
+- Minimal friction capture to Anytype
+- Auto-tagging based on content
+- Link to related notes
+
+### Knowledge Retrieval
+- Semantic search across notes
+- Tag-based filtering
+- Connection discovery
+
+### Resource Organization
+- PARA Resources category management
+- Topic clustering
+- Archive maintenance
+
+### Documentation Management
+- Technical docs organization
+- Version tracking
+- Cross-reference linking
+
+## Integration Points
+
+- **Anytype**: Primary storage (Resources type)
+- **task-management**: Link notes to projects/areas
+- **research**: Save research findings
+
+## Quick Commands (Future)
+
+| Command | Description |
+|---------|-------------|
+| `note: [content]` | Quick capture |
+| `find notes on [topic]` | Search knowledge base |
+| `link [note] to [note]` | Create connection |
+| `organize [tag/topic]` | Cluster related notes |
+
+## Anytype Types
+
+- `note` - Quick captures
+- `resource` - Organized reference material
+- `document` - Formal documentation
+
+## Notes
+
+Expand based on actual note-taking patterns. Consider integration with mem0-memory skill for AI-assisted recall.