Render images in help pages.

app/controllers/help_controller.rb

@@ -5,8 +5,12 @@ class HelpController < ApplicationController
   def show
     @category = params[:category]
     @file = params[:file]
+    format = params[:format] || 'md'
+    file_path = Rails.root.join('doc', @category, @file + ".#{format}")
 
-    if File.exists?(Rails.root.join('doc', @category, @file + '.md'))
+    if %w(png jpg jpeg gif).include?(format)
+      send_file file_path, disposition: 'inline'
+    elsif File.exists?(file_path)
       render 'show'
     else
       not_found!

config/routes.rb

@@ -34,6 +34,7 @@ Gitlab::Application.routes.draw do
 
   get 'help'                  => 'help#index'
   get 'help/:category/:file'  => 'help#show', as: :help_page
+  get 'help/:category/*file'  => 'help#show'
   get 'help/shortcuts'
 
   #

features/steps/help.rb

@@ -8,7 +8,7 @@ class Spinach::Features::Help < Spinach::FeatureSteps
   end
 
   step 'I visit the "Rake Tasks" help page' do
-    visit help_page_path("raketasks", "maintenance")
+    visit help_page_path("raketasks", "maintenance.md")
   end
 
   step 'I should see "Rake Tasks" page markdown rendered' do