Trivial typofix

Author: sportsman701

README.md

@@ -82,7 +82,7 @@ $ rails webpacker:install
 $ rails webpacker:install:react
 $ rails generate react:install
 ```
-Note: For Rails 6, You don't need to add `javascript_pack_tag` as in Step 4. Since its already added by default.
+Note: For Rails 6, You don't need to add `javascript_pack_tag` as in Step 4. Since it's already added by default.
 
 ###### Rails 5.x:
 ```