Add redirect for /styleguide

Adds a development-only route for `/styleguide` as an alias to
`/assets/styleguide.html`.

config/routes.rb

@@ -573,4 +573,9 @@ OpenProject::Application.routes.draw do
   get '/robots' => 'homescreen#robots', defaults: { format: :txt }
 
   root to: 'account#login'
+
+  # Development route for styleguide
+  if Rails.env.development?
+    get '/styleguide' => redirect('/assets/styleguide.html')
+  end
 end

frontend/doc/BUILD.md

@@ -37,4 +37,4 @@ On the Rails side, both frameworks are included as gems - see the `./Gemfile` -
 
 ## Living Styleguide
 
-The styleguide is rendered as part of the Rails stack at `/assets/styleguide.html`. Please see [their GitHub](https://github.com/livingstyleguide/livingstyleguide) for more information.
+The styleguide is rendered as part of the Rails stack at `/styleguide` (`RAILS_ENV=development` only). Please see [their GitHub](https://github.com/livingstyleguide/livingstyleguide) for more information.

frontend/doc/README.md

@@ -8,7 +8,7 @@ once webpack has completed.
 
 ## Living Style Guide
 
-The style guide is available as part of the Rails development server at: <http://localhost:5000/assets/styleguide.html>.
+The style guide is available as part of the Rails development server at: <http://localhost:5000/styleguide>.
 
 ## Changing or updating Dependencies