make dir for 2021 and template

AoC2021/template.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+
+import sys
+
+
+if __name__ == '__main__':
+    inputs  open(sys.argv[1]).read().split('\n\n')
+
+    # challenge 1
+    res1 = ""
+    print("challenge 1:" + + "\n")
+
+    # challenge 2
+    res2 = ""
+    print("challenge 2:" + + "\n")
+