Close Project in Arcmap

Idea created by Georgie.Cassar on Sep 15, 2014
    When I have finished working on an Arcmap project, I want to close it but simply leave ArcMap open. I want to leave Arcmap open because it takes so long to start up. Currently to close a project I need to open a new blank project which takes a while as well.  A simple CLose Project command in the File menu would suffice.