chore: add changeset for phase 8 DX improvements

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

Author: giovaborgogno

.changeset/event-docs-cli-dx.md

@@ -0,0 +1,10 @@
+---
+"@trigger.dev/sdk": patch
+"trigger.dev": patch
+---
+
+Add event system documentation, CLI commands, and developer experience improvements.
+New `rules/4.4.0/events.md` documentation covering all event features.
+CLI `trigger events list` and `trigger events publish` commands.
+JSDoc on `createEvent()` and `event()` with usage examples.
+Reference project `references/event-system/` demonstrating all event patterns.