README: move structure overview to the top

It now appears in its own section, serving as a quick way to understand
what is in the repository.

README.md

@@ -27,6 +27,15 @@ Releases are tagged periodically from active branches and are versioned 3.x
 corresponding to Origin releases 1.x. We unfortunately started with 3.0 and it's
 not practical to start over at 1.0.
 
+## Directory structure
+
+- [bin/cluster](https://github.com/openshift/openshift-ansible/tree/master/bin/cluster) - Python script to easily create clusters
+- [docs/](https://github.com/openshift/openshift-ansible/tree/master/docs) - documentation for the project
+- [filter_plugins/](https://github.com/openshift/openshift-ansible/tree/master/filter_plugins) - custom filters used to manipulate data in Ansible
+- [inventory/](https://github.com/openshift/openshift-ansible/tree/master/inventory) - Ansible dynamic inventory scripts
+- [playbooks/](https://github.com/openshift/openshift-ansible/tree/master/playbooks) - host-type Ansible playbooks (launch, config, destroy, vars)
+- [roles/](https://github.com/openshift/openshift-ansible/tree/master/roles) - shareable Ansible tasks
+
 ## Setup
 
 1. Install base dependencies:
@@ -55,14 +64,6 @@ not practical to start over at 1.0.
 - Build
   - [How to build the openshift-ansible rpms](BUILD.md)
 
-- Directory Structure:
-  - [bin/cluster](https://github.com/openshift/openshift-ansible/tree/master/bin/cluster) - python script to easily create clusters
-  - [docs](https://github.com/openshift/openshift-ansible/tree/master/docs) - Documentation for the project
-  - [filter_plugins/](https://github.com/openshift/openshift-ansible/tree/master/filter_plugins) - custom filters used to manipulate data in Ansible
-  - [inventory/](https://github.com/openshift/openshift-ansible/tree/master/inventory) - houses Ansible dynamic inventory scripts
-  - [playbooks/](https://github.com/openshift/openshift-ansible/tree/master/playbooks) - houses host-type Ansible playbooks (launch, config, destroy, vars)
-  - [roles/](https://github.com/openshift/openshift-ansible/tree/master/roles) - shareable Ansible tasks
-
 ## Contributing
 
 - [Best Practices Guide](https://github.com/openshift/openshift-ansible/blob/master/docs/best_practices_guide.adoc)