Note added for rails command in rails guide doc [ci skip] (rails#54461)

Co-authored-by: Petrik de Heus <[email protected]>

Author: ritaamritkar1212

guides/source/getting_started.md

@@ -182,6 +182,9 @@ This will initially create the application's database.
 $ bin/rails server
 ```
 
+NOTE: When we run commands inside an application directory, we should use
+`bin/rails`. This makes sure the application's version of Rails is used.
+
 This will start up a web server called Puma that will serve static files and
 your Rails application: