modifing tag line to give a better hint of mission and vision for the pr...

This is a copy change to the homepage that melds in our discussions around mission and vision. I have decided to be a bit shorter in describing these, rather than the long winded "our mission is, our vision is".

Based on feedback from the last steering committee call I've adopted for the terminology about being able to represent, and moved away from outlining that we will visualise everything, hope people like this, if not we can revert.