Use bin/rails instead of global rails command [ci-skip]

Author: jonathanhefner

guides/source/active_record_postgresql.md

@@ -579,14 +579,14 @@ To use the Rails model generator for a table using UUID as the primary key, pass
 For example:
 
 ```bash
-$ rails generate model Device --primary-key-type=uuid kind:string
+$ bin/rails generate model Device --primary-key-type=uuid kind:string
 ```
 
 When building a model with a foreign key that will reference this UUID, treat
 `uuid` as the native field type, for example:
 
 ```bash
-$ rails generate model Case device_id:uuid
+$ bin/rails generate model Case device_id:uuid
 ```
 
 Indexing

guides/source/security.md

@@ -50,7 +50,7 @@ authentication`. Here are all of the files the generator modifies and new files
 it adds:
 
 ```bash
-$ rails generate authentication
+$ bin/rails generate authentication
       invoke  erb
       create    app/views/passwords/new.html.erb
       create    app/views/passwords/edit.html.erb