Change ansible playbooks best practices URL

The before URL was 404.

website/content/docs/provisioning/ansible_intro.mdx

@@ -57,7 +57,7 @@ Vagrant.configure("2") do |config|
 end
 ```
 
-Since an Ansible playbook can include many files, you may also collect the related files in a [directory structure](https://docs.ansible.com/playbooks_best_practices.html#directory-layout) like this:
+Since an Ansible playbook can include many files, you may also collect the related files in a [directory structure](https://docs.ansible.com/ansible/2.8/user_guide/playbooks_best_practices.html#directory-layout) like this:
 
 ```text
 .