make: add makefile with some build/smoketest tasks

Signed-off-by: deadprogram <ron@hybridgroup.com>

Makefile

@@ -0,0 +1,18 @@
+
+clean:
+	@rm -rf build
+
+FMT_PATHS = ./
+
+fmt-check:
+	@unformatted=$$(gofmt -l $(FMT_PATHS)); [ -z "$$unformatted" ] && exit 0; echo "Unformatted:"; for fn in $$unformatted; do echo "  $$fn"; done; exit 1
+
+smoke-test:
+	@mkdir -p build
+	tinygo build -target pico-w -size short -o build/test.uf2 ./rp2-pio/examples/blinky
+	tinygo build -target pico-w -size short -o build/test.uf2 ./rp2-pio/examples/i2s
+	tinygo build -target pico-w -size short -o build/test.uf2 ./rp2-pio/examples/pulsar
+	tinygo build -target pico-w -size short -o build/test.uf2 ./rp2-pio/examples/tufty
+	tinygo build -target pico-w -size short -o build/test.uf2 ./rp2-pio/examples/ws2812b
+
+test: clean fmt-check smoke-test