CORE:  extended base to permissions and workflow + README

## Ready State:  YES

Related JIRA ticket:  https://imagex.atlassian.net/browse/LDC-228

## Requirements & Dependencies
* imagex_group
* imagex_addthis
* imagex_permissions

## Deployment Instructions

* Merge code.

## Usage/Test Instructions

* Confirm imagex group contains 3 extension modules, and installs as default. Confirm extension modules when enabled add appropriate extensions (like permissions). Confirm READMEs for base and extension files are to template standards