Implemented a QuadTree and a test

tests/QuadTree.test.c

@@ -0,0 +1,25 @@
+#include "../src/rand/xoshiro256.h"
+#include <stdio.h>
+#include "../src/QuadTree/QuadTree.h"
+
+static QuadTree tree;
+
+typedef struct Particle_s {
+        QuadTreeLeaf position;
+} Particle;
+
+static Particle particles[100];
+
+int main()
+{
+        QuadTree_Create(&tree, 10000, 10000, NULL);
+
+        Xoshiro256State rand_state = { 0, 10, 0, 0 };
+
+        for (size_t i = 0; i < sizeof(particles) / sizeof(particles[0]); i++) {
+                particles[i].position.x = xoshiro256_next(&rand_state) % 10000;
+                particles[i].position.y = xoshiro256_next(&rand_state) % 10000;
+                printf("%f %f\n", particles[i].position.y, particles[i].position.x);
+                QuadTree_Insert(&tree, &particles[i].position);
+        }
+}