Disable spell-checking on the metrics dictionary

This page can't be brought up to GitLab tone and style because it
is autogenerated by a script we can't easily change. Disable spell
checking on this page.

doc/development/usage_ping.md

@@ -6,7 +6,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 
 # Usage Ping Guide
 
-> - More statistics were added in GitLab Ultimate 11.2.
+> Introduced in GitLab Ultimate 11.2, more statistics.
 
 This guide describes Usage Ping's purpose and how it's implemented.
 

doc/development/usage_ping/dictionary.md

@@ -10,6 +10,8 @@ info: To determine the technical writer assigned to the Stage/Group associated w
   Please do not edit this file directly, check generate_metrics_dictionary task on lib/tasks/gitlab/usage_data.rake.
 --->
 
+<!-- vale gitlab.Spelling = NO -->
+
 # Metrics Dictionary
 
 This file is autogenerated, please do not edit directly.

lib/gitlab/usage/docs/helper.rb

@@ -21,6 +21,8 @@ module Gitlab
 
               Please do not edit this file directly, check generate_metrics_dictionary task on lib/tasks/gitlab/usage_data.rake.
             --->
+
+            <!-- vale gitlab.Spelling = NO -->
           MARKDOWN
         end