Update README.md

Co-authored-by: Hiroki Kobayashi <3303362+koba-e964@users.noreply.github.com>

Author: matsu7874

README.md

@@ -13,7 +13,7 @@ Our first milestone is 2020/09/20, when the first ACL contest is planned.
 We aim to implement the same toolset as original ACL(C++) on the day.
 
 We are trying to implement with the same files by referring to the original ACL's hpp.
-After that we try to improve develop flow, tests, or utility.
+After that we try to improve our development flow, tests, or utilities.
 
 ## How to contribute