Add Quick Start docs and branch-specific Docker builds

- README.md: Add Quick Start section with full build sequence
- docker/README.md: Document branch-specific builds with git worktrees
- docker/build.sh: Use branch name for COMPOSE_PROJECT_NAME
- docker/docker-compose.yml: Remove hardcoded container_name

Each branch now gets isolated Docker containers/volumes, enabling
parallel development across git worktrees.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

docker/docker-compose.yml

@@ -3,7 +3,7 @@ services:
     build:
       context: ..
       dockerfile: docker/Dockerfile
-    container_name: kicad-wasm-builder
+    # Container name is auto-generated with project prefix (set in build.sh)
 
     # Resource limits (adjust based on your machine)
     deploy: