Fix doc links

app/views/admin/cohorts/_cohorts_table.html.haml

@@ -3,7 +3,7 @@
     User cohorts are shown for the last #{@cohorts[:months_included]}
     months. Only users with activity are counted in the cohort total; inactive
     users are counted separately.
-    = link_to icon('question-circle'), help_page_path('administration/usage_ping_and_cohorts', anchor: 'cohorts'), title: 'About this feature', target: '_blank'
+    = link_to icon('question-circle'), help_page_path('user/admin_area/user_cohorts', anchor: 'cohorts'), title: 'About this feature', target: '_blank'
 
 .table-holder
   %table.table

app/views/admin/cohorts/index.html.haml

@@ -9,7 +9,7 @@
     .bs-callout.bs-callout-warning.clearfix
       %p
         User cohorts are only shown when the
-        = link_to 'usage ping', help_page_path('administration/usage_ping_and_cohorts', anchor: 'usage-ping'), target: '_blank'
+        = link_to 'usage ping', help_page_path('user/admin_area/usage_statistics'), target: '_blank'
         is enabled. To enable it and see user cohorts,
         visit
         = succeed '.' do

doc/README.md

@@ -73,7 +73,7 @@ All technical content published by GitLab lives in the documentation, including:
 - [Sidekiq Troubleshooting](administration/troubleshooting/sidekiq.md) Debug when Sidekiq appears hung and is not processing jobs.
 - [System hooks](system_hooks/system_hooks.md) Notifications when users, projects and keys are changed.
 - [Update](update/README.md) Update guides to upgrade your installation.
-- [Usage ping and cohorts](administration/usage_ping_cohorts.md) Usage ping and cohorts
+- [User cohorts](user/admin_area/user_cohorts.md) View user activity over time.
 - [Web terminals](administration/integration/terminal.md) Provide terminal access to environments from within GitLab.
 - [Welcome message](customization/welcome_message.md) Add a custom welcome message to the sign-in page.