Add instructions for exiting Medley (#205)

* Add instructions for exiting Medley

* Add instructions for exiting Medley

* Add instructions for exiting Medley

* Add instructions for exiting Medley

Author: pamoroso

content/en/software/install-and-run/running-on-linux.md

@@ -53,6 +53,8 @@ The .deb package will install Medley as well as any other packages needed for Me
 	For first-time users: `medley --apps` or for WSL `medley --apps --vnc` is a good starting
 	point.  This will give you a fully populated Medley system, including the applications built on Medley such as Notecards and Rooms.
 
+4. To exit Medley execute `(IL:LOGOUT)` at the Lisp prompt.
+
 #### Notes:
 
 * By default, `medley` will create a directory in *$HOME/il*.  This will be used by the Medley

content/en/software/install-and-run/running-on-mac.md

@@ -58,6 +58,8 @@ There are many options to the `medley` command.  For a brief overview, run `./me
 
 For first-time users: `./medley -a -e -n` is a good starting	point.  This will give you a fully populated Medley system, including the applications built on Medley such as Notecards and Rooms.  It will start with a Interlisp Exec window (instead of the Xerox Common Lisp Exec window).
 
+To exit Medley execute `(IL:LOGOUT)` at the Lisp prompt.
+
 #### Notes:
 
 >By default, `medley` will create a directory in *$HOME/il*.  This will be used by the Medley system as its *LOGINDIR*.  Medley will start up with *LOGINDIR* as its current connected directory. 	It will load the personal init file (if any) from *LOGINDIR*/INIT or *LOGINDIR*/INIT.LCOM.  Finally,  Medley will use *LOGINDIR*/vmem/ to store its virtual memory file(s).  The location of *LOGINDIR* can be changed using the `--logindir` option to `medley`.	

content/en/software/install-and-run/running-on-win.md

@@ -47,6 +47,8 @@ The installation app will ask for the directory in which to install Medley.  Any
    cmd /C medley <flags and options>
    ```
 
+4. To exit Medley execute `(IL:LOGOUT)` at the Lisp prompt.
+
 Documentation for the `<flags and options>` to the `medley` command can be found [here](https://online.interlisp.org/downloads/man_medley.html)
 
 For first-time users: `medley --apps --interlisp --noscroll` or, equivalently, `medley -a -e -n` is a good starting point.  This will give you a fully populated Medley system, including the applications built on Medley such as Notecards and Rooms.

content/en/software/install-and-run/running-on-wsl.md

@@ -26,6 +26,8 @@ while the X Window on WSL will not so scale. The WSL packages also install the w
 package, which is used by Medley to connect to external browsers as described above.
 Aside from these two features, a non-WSL .deb package will install and run on WSL.
 
+To exit Medley execute `(IL:LOGOUT)` at the Lisp prompt.
+
 ## Accessing Medley for WSL
 
 1. Use a browser to download from the .deb package for your platform (i.e., "standard" WSL) and your machine architecture (X86_64, ARM64, or ARMv7) to `<deb_filepath>` from [the Medley downloads site](https://online.interlisp.org/downloads/medley_downloads.html)