how do i sign up for the email digest

The reason Ron Strong does not regard the LINK you provided as a solution to his question is that it merely says:
"To receive the email digest go to your Community Profile> Notification>Preferences"
but it's not the least bit obvious where the "Community Profile" is!

Ron Strong, I have figured this out. At least under Windows (probably Mac also, no idea about phones though), the button in the top right corner opens your "Community Profile." If you didn't customize your profile graphic, that button is a happy face. Mine is a light purple.

Click that and then click "Account and Privacy Settings" just below your email address. Then click "Notification Preferences" on the right. Here you can set many notifications for different things as either pop-up or email, but at the bottom of the list is a lone checkbox to turn on or off the email digests, which is, of course, what you're look for.