Reorganize code into library for reuse

lib/maze.c

@@ -0,0 +1,13 @@
+#include <mazemaker.h>
+#include "grid.h"
+#include "prim.h"
+
+void mazemaker_generate_maze(int width, int height, mazegrid_t* result) {
+    mazegrid_t g = mazegrid_new(width, height);
+    mazegrid_randomize(&g);
+    prim(&g, result);
+    mazegrid_free(&g);
+}
+void mazemaker_free_maze(mazegrid_t* maze) {
+    mazegrid_free(maze);
+}