new content images for books and about us

 On branch master

	deleted:    website/assets/img/david-wilmert.jpg
	new file:   website/assets/img/david-wilmert.png
	deleted:    website/assets/img/jeffrey-eakin-md.jpg
	new file:   website/assets/img/jeffrey-eakin-md.png
	new file:   website/assets/img/kris-walker.png
	modified:   website/assets/img/liz-walker.jpg
	modified:   website/assets/img/pinfinity-freedom-video.jpg
	modified:   website/assets/img/pinfinity-tutorial-video.jpg