Update README [ci skip]

README.md

@@ -69,7 +69,7 @@ This is useful when you want to edit templates without changing Rails configurat
 
 Change `config.consider_all_requests_local` to _false_ in `config/environments/development.rb`.
 
-```
+```ruby
 config.consider_all_requests_local = false
 ```
 
@@ -79,7 +79,7 @@ This simulates how your production app displays error pages so you can actually
 
 If you want to do some more things in a exceptions app, you can also write your own custom exceptions app:
 
-```
+```sh
 $ rails g rambulance:exceptions_app
 ```
 
@@ -123,8 +123,8 @@ Note that testing error pages is not encouraged in Rails as it leads to overuse
 
 ## Supported Versions
 
-* Ruby 2.3, 2,4, 2,5, 2.6, trunk, JRuby 9.2, and JRuby head
-* Rails 4.2, 5.0, 5.1, 5.2, 6.0 and edge
+* Ruby 2.3, 2,4, 2,5, 2.6, 2.7, 3.0, 3.1, and JRuby 9.3
+* Rails 4.2, 5.0, 5.1, 5.2, 6.0, 6.1, 7.0 and edge
 
 Rambulance doesn't work with Rails 3.1 and below since they don't provide a way to use a custom exceptions app.