Completed vector implementation and added sample usage

usage.c

@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include "src/vector.h"
+
+int main(void) {
+    // Create a vector of 5 integers
+    VectorResult res = vector_new(5, sizeof(int));
+    if (res.status != VECTOR_OK) {
+        printf("Error while creating vector: %s\n", res.message);
+
+        return 1;
+    }
+
+    Vector *vector = res.value.vector;
+
+    // Push some values
+    for (int idx = 0; idx <= 5; idx++) {
+        VectorResult add_res = vector_push(vector, &idx);
+        if (add_res.status != VECTOR_OK) {
+            printf("Error while adding elements: %s\n", add_res.message);
+
+            return 1;
+        }
+    }
+
+    // Print vector size and capacity
+    printf("Vector size: %zu\n", vector_size(vector));
+    printf("Vector capacity: %zu\n", vector_capacity(vector));
+
+    // Print the whole vector
+    for (size_t idx = 0; idx < vector_size(vector); idx++) {
+        VectorResult get_res = vector_get(vector, idx);
+        if (get_res.status == VECTOR_OK) {
+            int val = *(int *)get_res.value.element;
+            printf("vec[%zu] = %d\n", idx, val);
+        }
+    }
+
+    // Set an element at index 2
+    int new_val = 0xABABA;
+    VectorResult set_res = vector_set(vector, 2, &new_val);
+    if (set_res.status == VECTOR_OK) {
+        printf("vec[2] updated to %d\n", new_val);
+    }
+
+    // Pop last element
+    VectorResult pop_res = vector_pop(vector);
+    if (pop_res.status == VECTOR_OK) {
+        int val = *(int *)pop_res.value.element;
+        printf("Popped value: %d\n", val);
+    }
+
+    // Clear vector
+    VectorResult clear_res = vector_clear(vector);
+    if (clear_res.status == VECTOR_OK) {
+        printf("Vector cleared. New size is: %zu\n", vector_size(vector));
+    }
+
+    // Free vector
+    VectorResult free_res = vector_free(vector);
+    if (free_res.status != VECTOR_OK) {
+        printf("Error while freeing the vector: %s\n", free_res.message);
+    }
+
+    return 0;
+}