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

@@ -88,7 +88,7 @@ All technical content published by GitLab lives in the documentation, including:
 - [Repository restrictions](user/admin_area/settings/account_and_limit_settings.md#repository-size-limit) Define size restrictions for your repositories to limit the space they occupy in your storage device. Includes LFS objects.
 - [Auditor users](administration/auditor_users.md) Create auditor users, with read-only access to the entire system.
 - [Database load balancing](administration/database_load_balancing.md) Distribute database queries amongst multiple database servers.
-- [Usage ping and cohorts](administration/usage_ping_and_cohorts.md) Usage ping and cohorts
+- [User cohorts](user/admin_area/user_cohorts.md) View user activity over time.
 
 ## Contributor documentation