update API doc with +API (h1 heading)

d5eb6666 · Marcia Ramos · 180ec711 · d5eb6666 · d5eb6666 · d5eb6666
--- a/doc/api/access_requests.md
+++ b/doc/api/access_requests.md
-# Group and project access requests
+# Group and project access requests API

 >**Note:** This feature was introduced in GitLab 8.11


--- a/doc/api/enviroments.md
+++ b/doc/api/enviroments.md
-# Environments
+# Environments API

 ## List environments


--- a/doc/api/groups.md
+++ b/doc/api/groups.md
-# Groups
+# Groups API

 ## List groups


--- a/doc/api/issues.md
+++ b/doc/api/issues.md
-# Issues
+# Issues API

 Every API call to issues must be authenticated.


--- a/doc/api/keys.md
+++ b/doc/api/keys.md
-# Keys
+# Keys API

 ## Get SSH key with user by ID of an SSH key


--- a/doc/api/labels.md
+++ b/doc/api/labels.md
-# Labels
+# Labels API

 ## List labels


--- a/doc/api/members.md
+++ b/doc/api/members.md
-# Group and project members
+# Group and project members API

 **Valid access levels**


--- a/doc/api/merge_requests.md
+++ b/doc/api/merge_requests.md
-# Merge requests
+# Merge requests API

 ## List merge requests


--- a/doc/api/notification_settings.md
+++ b/doc/api/notification_settings.md
-# Notification settings
+# Notification settings API

 >**Note:** This feature was [introduced][ce-5632] in GitLab 8.12.


--- a/doc/api/projects.md
+++ b/doc/api/projects.md
-# Projects
+# Projects API


 ### Project visibility level

--- a/doc/api/settings.md
+++ b/doc/api/settings.md
-# Application settings
+# Application settings API

 These API calls allow you to read and modify GitLab instance application
 settings as appear in `/admin/application_settings`. You have to be an

--- a/doc/api/snippets.md
+++ b/doc/api/snippets.md
-# Snippets
+# Snippets API

 > [Introduced][ce-6373] in GitLab 8.15.


--- a/doc/api/todos.md
+++ b/doc/api/todos.md
-# Todos
+# Todos API

 > [Introduced][ce-3188] in GitLab 8.10.


--- a/doc/api/users.md
+++ b/doc/api/users.md
-# Users
+# Users API

 ## List users