Add Makefile with target to add git submodules and usage instructions

Makefile

@@ -0,0 +1,48 @@
+.PHONY: add-submodule help
+
+help:
+	@echo "Available targets:"
+	@echo "  add-submodule - Add a git submodule"
+	@echo "    Usage: make add-submodule <git-url> [directory-name]"
+
+%:
+	@:
+
+add-submodule:
+	@ARGS="$(filter-out $@,$(MAKECMDGOALS))"; \
+	URL=$$(echo $$ARGS | awk '{print $$1}'); \
+	DIR=$$(echo $$ARGS | awk '{print $$2}'); \
+	if [ -z "$$URL" ]; then \
+		echo "Error: URL is required. Usage: make add-submodule <git-url> [directory-name]"; \
+		exit 1; \
+	fi; \
+	if [ -z "$$DIR" ]; then \
+		REPO_NAME=$$(echo $$URL | awk -F'/' '{print $$NF}' | sed 's/\.git$$//'); \
+		SUBMODULE_DIR=$$REPO_NAME; \
+	else \
+		SUBMODULE_DIR=$$DIR; \
+	fi; \
+	ADD_OUTPUT=$$(git submodule add $$URL $$SUBMODULE_DIR 2>&1); \
+	ADD_EXIT=$$?; \
+	if [ $$ADD_EXIT -ne 0 ]; then \
+		if echo "$$ADD_OUTPUT" | grep -q "A git directory for.*is found locally"; then \
+			echo "Warning: Submodule directory already exists. Using --force to reuse it."; \
+			git submodule add --force $$URL $$SUBMODULE_DIR 2>&1 || { \
+				echo "Error: Failed to add submodule with --force"; \
+				exit 1; \
+			}; \
+		else \
+			echo "$$ADD_OUTPUT"; \
+			exit $$ADD_EXIT; \
+		fi; \
+	fi; \
+	UPDATE_OUTPUT=$$(git submodule update --init --recursive $$SUBMODULE_DIR 2>&1); \
+	UPDATE_EXIT=$$?; \
+	if [ $$UPDATE_EXIT -ne 0 ]; then \
+		if echo "$$UPDATE_OUTPUT" | grep -q "empty repository\|yet to be born"; then \
+			echo "Warning: Empty repository detected. Submodule added but not checked out."; \
+		else \
+			echo "$$UPDATE_OUTPUT"; \
+			exit $$UPDATE_EXIT; \
+		fi; \
+	fi