Add script (new_prob.py) to create problem skeleton

new_prob.py

@@ -0,0 +1,19 @@
+import sys
+import json
+from pathlib import Path
+
+if __name__ == '__main__':
+    if len(sys.argv) != 2:
+        print(f'Usage: python {__file__} <problem_name>')
+        exit(0)
+    problem_name = sys.argv[1]
+    problem_root = Path('problem')
+    problem_dir = problem_root / problem_name
+    problem_dir.mkdir()
+    (problem_dir / 'src').mkdir()
+    (problem_dir / 'testcase').mkdir()
+    meta = problem_dir / 'meta.json'
+    json.dump({
+        'language': 0,
+        'tasks': [],
+    }, meta.open('w'))