docs: typo Flash --> Flask (#15)

donhui · yugasun · commit 744ccd08f2f1 · 2020-12-21T19:11:28.000+08:00
diff --git a/README.md b/README.md
@@ -33,7 +33,7 @@ app = Flask(__name__)
 
 @app.route("/")
 def index():
-    return "Hello Flash"
+    return "Hello Flask"
 
 @app.route("/users")
 def users():
