Add pkg.go.dev badge and package doc comment

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

Author: phiat

README.md

@@ -1,5 +1,7 @@
 # claude-esp
 
+[![Go Reference](https://pkg.go.dev/badge/github.com/phiat/claude-esp.svg)](https://pkg.go.dev/github.com/phiat/claude-esp)
+
 Stream Claude Code's hidden output (thinking, tool calls, subagents) to a separate terminal in real-time.
 
 ![claude-esp screenshot](docs/screenshot.png)

main.go

@@ -1,3 +1,15 @@
+// Claude-esp streams Claude Code's hidden output (thinking, tool calls, subagents)
+// to a separate terminal in real-time.
+//
+// Usage:
+//
+//	claude-esp              # Watch all active sessions
+//	claude-esp -n           # Skip history, live only
+//	claude-esp -s <ID>      # Watch a specific session
+//	claude-esp -a           # List active sessions
+//	claude-esp -l           # List recent sessions
+//
+// See https://github.com/phiat/claude-esp for full documentation.
 package main
 
 import (