Update README.md (#391)

diff --git a/webdev/README.md b/webdev/README.md
index dfeffb2..2844422 100644
--- a/webdev/README.md
+++ b/webdev/README.md
@@ -30,7 +30,7 @@
 ```console
 $ pub global activate webdev
 # or
-$ flutter packages pub global activate webdev
+$ flutter pub global activate webdev
 ```
 
 Learn more about activating and using packages [here][pub global].