chore: add Makefile for build and lint commands

helpful for a rust newbie like myself to easily run test commands and debug container builds

Makefile

@@ -0,0 +1,42 @@
+install-insta:
+	cargo install --list | grep -q cargo-insta || cargo install cargo-insta
+
+# when adding or modifying ./examples tests, you'll need to run this
+review-snapshots: install-insta
+	cargo insta test --review --test generate_plan_tests
+
+lint:
+	cargo fmt --all -- --check
+	cargo check
+	cargo clippy
+	cd docs && yarn lint
+
+# run locally to fix all linting errors before pushing
+lint-fix:
+	cargo fmt --all
+	cargo check
+	cargo clippy --fix --allow-dirty
+	cd docs && yarn lint
+
+# where TEST_TARGET=test_python_asdf_poetry, helpful for rerunning failed tests on CI
+test-single:
+	RUST_LOG=DEBUG RUST_BACKTRACE=1 cargo test --package nixpacks --test docker_run_tests -- $(TEST_TARGET) --exact
+
+# ex: TEST_TARGET=examples/python-postgres
+build-single:
+	if [ ! -d "$(TEST_TARGET)" ]; then \
+		echo "Error: $(TEST_TARGET) is not a valid directory."; \
+		exit 1; \
+	fi
+
+	RUST_LOG=DEBUG RUST_BACKTRACE=1 cargo run -- build $(TEST_TARGET) --name node
+
+debug-single:
+	if [ ! -d "$(TEST_TARGET)" ]; then \
+		echo "Error: $(TEST_TARGET) is not a valid directory."; \
+		exit 1; \
+	fi
+
+	cargo run -- build $(TEST_TARGET) --out $(TEST_TARGET)
+	build_debug_cmd="$(shell sed 's/docker build/BUILDX_EXPERIMENTAL=1 docker buildx debug --invoke bash build/' $(TEST_TARGET)/.nixpacks/build.sh)" && \
+		eval "$$build_debug_cmd"