CAEN URL Change

[hardy-ethan]

What
CAEN URLs have changed. Old URL (login.engin.umich.edu) seems to still work, but I worry that it will be turned off as it has been replaced in CAEN documentation.

Source: https://caen.engin.umich.edu/connect/linux-login-service/

Where
CAEN, Emacs, and style setup tutorials.

Current
login.engin.umich.edu is used as the URL

Proposed
Change to the new broad (i.e. not on-campus) login URL login-course.engin.umich.edu. Include a note on the warning that may be generated from the shared host key between the new and old URL.

[hardy-ethan]

Implemented #202