Architecture section

Some work on the architecture section.

docs/architecture/components/ansible/index.md

-# Ansible
+# Ansible
\ No newline at end of file
+
+Ansible is responsible of:
+
+- compiling, deploying and deleting configuration on targeted devices
+- gather operational information from the targeted devices
+
+The Ansible subsystem is composed by three main functional parts:
+
+- A plugin that is responsible for exposing the Ansible engine to workflow orchestrator via APIs
+- A set of Ansible roles and playbooks that interacts with the network elements
+- A set of global variables stored in a Git repository that partially build the Ansible Inventory
+