Add erlang binding (#54)

* add erlang support

* add erlang support for windows

* add erlang ci for linux and windows

erlang/Makefile

@@ -0,0 +1,21 @@
+ifndef MIX_APP_PATH
+	MIX_APP_PATH=$(shell pwd)
+endif
+
+PRIV_DIR = $(MIX_APP_PATH)/priv
+RUAPU_SO = $(PRIV_DIR)/ruapu_nif.so
+C_SRC = $(shell pwd)/c_src
+
+.DEFAULT_GLOBAL := build
+
+build: $(RUAPU_SO)
+	@echo > /dev/null
+
+$(RUAPU_SO): $(C_SRC)/ruapu.c
+	@ cmake -S . -B "$(PRIV_DIR)/cmake_ruapu" \
+		-DCMAKE_BUILD_TYPE=Release \
+		-DC_SRC=$(C_SRC) \
+		-DMIX_APP_PATH=$(MIX_APP_PATH) \
+		-DCMAKE_INSTALL_PREFIX=$(PRIV_DIR)
+	@ cmake --build "$(PRIV_DIR)/cmake_ruapu" --config Release
+	@ cp "$(PRIV_DIR)/cmake_ruapu/ruapu_nif.so" $(RUAPU_SO)