docs: update CHANGELOG for v0.6.0 (RSS feeds)

Documents Phase 5 RSS feed implementation:
- RSS 2.0 feed generation
- Server-side caching with ETag support
- Configuration options
- Standards compliance
- Test coverage improvements
- Related documentation references

CHANGELOG.md

@@ -7,6 +7,51 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.6.0] - 2025-11-19
+
+### Added
+- **RSS Feed Generation**: Standards-compliant RSS 2.0 feed for published notes
+- RSS feed module (`starpunk/feed.py`) with feed generation functions
+- GET `/feed.xml` route for RSS feed access
+- Server-side feed caching (5-minute default, configurable)
+- ETag support for efficient feed updates
+- Cache-Control headers for client-side caching
+- RSS feed auto-discovery link in HTML templates
+- RSS link in site navigation
+- Comprehensive RSS feed test suite (44 tests)
+
+### Configuration
+- `FEED_MAX_ITEMS`: Maximum items in RSS feed (default: 50)
+- `FEED_CACHE_SECONDS`: Server-side cache duration in seconds (default: 300)
+
+### Features
+- RSS 2.0 compliant XML generation using feedgen library
+- RFC-822 date formatting for RSS pubDate elements
+- Intelligent note title extraction (first line or timestamp fallback)
+- HTML content in CDATA sections for feed readers
+- Atom self-link for feed discovery
+- Only published notes included in feed
+- Absolute URLs for all feed item links
+
+### Testing
+- 88% overall test coverage (up from 87%)
+- 96% coverage for feed module
+- 449/450 tests passing (99.78% pass rate)
+- Test isolation with automatic cache clearing
+- Unicode and special character handling verified
+
+### Standards Compliance
+- RSS 2.0 specification compliant
+- RFC-822 date format for timestamps
+- IndieWeb feed discovery support
+- W3C Feed Validator compatible
+
+### Related Documentation
+- ADR-014: RSS Feed Implementation Strategy
+- ADR-015: Phase 5 Implementation Approach
+- Phase 5 design documentation
+- Phase 5 quick reference guide
+
 ## [0.5.2] - 2025-11-18
 
 ### Fixed