Code review comments applied

app/services/projects/create_from_template_service.rb

@@ -21,7 +21,7 @@ module Projects
 
     def template_name
       strong_memoize(:template_name) do
-        params.delete(:template_name)
+        params.delete(:template_name).presence
       end
     end
   end

doc/gitlab-basics/create-project.md

@@ -36,6 +36,13 @@
 
 1. Click **Create project**.
 
+## Custom project templates
+> [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/issues/6860) in [GitLab Edition Premium][ee] 11.2
+
+When you create a new project, creating it based on custom project templates is a convenient option to bootstrap from an existing project boilerplate. The administration setting to configure a GitLab group that serves as template source can be found under **Admin > Settings > Custom project templates**.
+
+Within this section, you can configure the group where all the custom project templates are sourced. Every project under the group namespace will be available to the user if they have access to them. For example: Every public project in the group will be available to the user. However, private projects will be available only if the user is authorized.
+
 ## Push to create a new project
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab-ce/issues/26388) in GitLab 10.5.

lib/gitlab/template_helper.rb

 module Gitlab
   module TemplateHelper
+    include Gitlab::Utils::StrongMemoize
+
     def prepare_template_environment(file_path)
       return unless file_path.present?