Completed vector implementation and added sample usage

Makefile

@@ -0,0 +1,31 @@
+CC = gcc
+CFLAGS = -Wall -Wextra -Werror -pedantic-errors -fstack-protector-strong \
+	-fsanitize=address -fsanitize=undefined -fstack-clash-protection \
+	-Wwrite-strings -std=c99
+LDFLAGS = -fsanitize=address -fsanitize=undefined
+
+SRC_DIR = src
+OBJ_DIR = obj
+
+TARGET = usage
+LIB_OBJS = $(OBJ_DIR)/vector.o
+PROG_OBJS = $(OBJ_DIR)/usage.o
+
+.PHONY: all clean
+
+all: $(TARGET)
+
+$(TARGET): $(PROG_OBJS) $(LIB_OBJS)
+	$(CC) $(CFLAGS) -o $@ $^
+
+$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c | $(OBJ_DIR)
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+$(OBJ_DIR)/%.o: %.c | $(OBJ_DIR)
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+$(OBJ_DIR):
+	mkdir -p $(OBJ_DIR)
+
+clean:
+	rm -rf $(OBJ_DIR) $(TARGET)