Display Signed-in users content is available even if unauthenticated

Feature Request Summary: 

Indicate in the directory & search result that Signed-in users only content is available and direct user to sign in.

Description/Use Cases: 

We have Signed-in users only content per our policy of not sharing beta/upcoming information to the public. However, we'd like any user (Everyone) to know the content is available, they just need to sign in.

Business impact of limitation or missing feature:

Both internal and external users wonder why they can't find the resource if they're not signed-in.

Other necessary information or resources:

n/a