Add devcontainer configuration for automatic bd setup

- Create .devcontainer/devcontainer.json with Go 1.23 environment
- Add setup.sh to build bd from source and install git hooks
- Add devcontainer README with documentation
- Update main README to mention devcontainer support
- Resolves bd-ry1u and GitHub issue #229

.devcontainer/setup.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+set -e
+
+echo "🔧 Building bd from source..."
+go build -o bd ./cmd/bd
+
+echo "📦 Installing bd globally..."
+sudo mv bd /usr/local/bin/bd
+sudo chmod +x /usr/local/bin/bd
+
+echo "✅ Verifying bd installation..."
+bd --version
+
+echo "🎯 Initializing bd (non-interactive)..."
+if [ ! -d .beads ]; then
+  bd init --quiet
+else
+  echo "bd already initialized"
+fi
+
+echo "🪝 Installing git hooks..."
+if [ -f examples/git-hooks/install.sh ]; then
+  bash examples/git-hooks/install.sh
+  echo "Git hooks installed successfully"
+else
+  echo "⚠️  Git hooks installer not found, skipping..."
+fi
+
+echo "📚 Installing Go dependencies..."
+go mod download
+
+echo "✨ Development environment ready!"
+echo "Run 'bd ready' to see available tasks"