docs: Add documentation for --install-shortcut and keyboard toggle features

Updated README.md and autocode.md to include:
- Installation and usage of --install-shortcut command
- Toggle automation with Ctrl+A+A keyboard shortcut
- New feature highlights in Features section
- Usage examples for keyboard shortcut setup

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

autocode.md

@@ -101,11 +101,15 @@ Session Commands:
 Service Commands:
 - autoclaude start - Start orchestrator (auto-detect mode)
 - autoclaude start <session> <window> - Start monitoring specific session
+- autoclaude start toggle - Toggle automation for active pane
 - autoclaude stop - Stop all monitoring
 - autoclaude stop <session> <window> - Stop monitoring specific session
 - autoclaude status - Check orchestrator status
 - autoclaude logs - Follow orchestrator logs
 
+Setup Commands:
+- autoclaude --install-shortcut - Install Ctrl+A+A keyboard shortcut in tmux config
+
 ### Usage Examples
 
 Detect all Claude Code sessions:
@@ -133,6 +137,17 @@ Check orchestrator status:
 autoclaude status
 ```
 
+Install keyboard shortcut:
+```bash
+autoclaude --install-shortcut
+```
+
+Toggle automation for active pane:
+```bash
+autoclaude start toggle
+# Or use keyboard shortcut in tmux: Ctrl+A+A
+```
+
 View live logs:
 ```bash
 autoclaude logs