Docs for SERVER-34584: Update the default cloud free monitoring endpoint to final location

Description:

Need to document free monitoring feature

Scope of changes:

Impact to other docs outside of this product:

MVP:

Resources:

Engineering Ticket Description:

Update the default cloud free monitoring endpoint to the final location. It is currently hard-coded to a testing default here

CC: jonathan.balsano, duncan.armstrong, john.morales

Also add connect announce and test.