Make section headings consistent

doc/README.md

@@ -9,7 +9,7 @@ description: 'Learn how to use and administer GitLab, the most scalable Git-base
 </div>
 <!-- the div above will not display on the docs site but will display on /help -->
 
-# GitLab Documentation
+# GitLab Docs
 
 Welcome to [GitLab](https://about.gitlab.com/) Documentation.
 

doc/administration/index.md

@@ -2,7 +2,7 @@
 description: 'Learn how to install, configure, update, and maintain your GitLab instance.'
 ---
 
-# Administrator documentation **(CORE ONLY)**
+# Administrator Docs **(CORE ONLY)**
 
 Learn how to administer your self-managed GitLab instance.
 

doc/api/README.md

-# GitLab API
+# API Docs
 
 Automate GitLab via a simple and powerful API.
 

doc/development/README.md

@@ -3,7 +3,7 @@ comments: false
 description: 'Learn how to contribute to GitLab.'
 ---
 
-# GitLab development guides
+# Contributor and Development Docs
 
 ## Get started!
 

doc/subscriptions/index.md

@@ -2,7 +2,7 @@
 type: index, reference
 ---
 
-# Customers
+# Customer Docs
 
 This section contains information for:
 

doc/user/index.md

@@ -2,7 +2,7 @@
 description: 'Read through the GitLab User documentation to learn how to use, configure, and customize GitLab and GitLab.com to your own needs.'
 ---
 
-# User documentation
+# User Docs
 
 Welcome to GitLab! We're glad to have you here!