Add --expanded option to "rails routes"

When using rails routes with small terminal or complicated routes it can be
very difficult to understand where is the element listed in header. psql
had the same issue, that's why they created "expanded mode" you can
switch using `\x` or by starting psql with
```
-x
--expanded

    Turn on the expanded table formatting mode. This is equivalent to the \x command.
```
The output is similar to one implemented here for rails routes:

db_user-# \du
List of roles
-[ RECORD 1 ]----------------------------------------------
Role name  | super
Attributes | Superuser, Create role, Create DB
Member of  | {}
-[ RECORD 2 ]----------------------------------------------
Role name  | role
Attributes | Superuser, Create role, Create DB, Replication
Member of  | {}

1 files changed, 1 insertions, 1 deletions

diff --git a/guides/source/routing.md b/guides/source/routing.md
index 1e75cbf362..98aa841938 100644
--- a/guides/source/routing.md
+++ b/guides/source/routing.md
@@ -1183,7 +1183,7 @@ $ bin/rails routes -c Comments
 $ bin/rails routes -c Articles::CommentsController
 ```
 
-TIP: You'll find that the output from `rails routes` is much more readable if you widen your terminal window until the output lines don't wrap.
+TIP: You'll find that the output from `rails routes` is much more readable if you widen your terminal window until the output lines don't wrap. You can also use --expanded option to turn on the expanded table formatting mode.
 
 ### Testing Routes