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/build.sh

@@ -11,6 +11,11 @@ set -e
 
 cd "$(dirname "$0")/.."
 
+# Use branch name as Docker Compose project name for isolated containers/volumes
+BRANCH_NAME=$(git rev-parse --abbrev-ref HEAD | tr '/' '-' | tr '[:upper:]' '[:lower:]')
+export COMPOSE_PROJECT_NAME="kicad-wasm-${BRANCH_NAME}"
+echo "Using Docker project: ${COMPOSE_PROJECT_NAME}"
+
 # Add -j 10 by default if no -j flag is given
 ARGS=("$@")
 if [[ ! " ${ARGS[*]} " =~ " -j " ]]; then