add test-app target

tests/app.c

@@ -0,0 +1,25 @@
+//
+// Created by maxim on 27.11.23.
+//
+
+#include <yandex_disk_api.h>
+#include <stdio.h>
+
+int main() {
+    char token[1024];
+
+    printf("Enter OAuth token: ");
+    fgets(token, sizeof(token), stdin);
+
+    yadisk_api_client* client = &(yadisk_api_client){
+            .token = token
+    };
+
+    yadisk_disk_info yadisk_disk_info;
+
+    yadisk_get_disk(client, &yadisk_disk_info);
+
+    printf("Total disk size: %lu", yadisk_disk_info.total_space);
+
+    return 0;
+}