[FAB-4210] Add note about shared volumes

All of the samples configurations make use
of shared volumes for Docker.  This can be
tricky for Windows and macOS users if they
are not familiar with how this works with
Docker Toolbox and/or Docker for Windows and
macOS.
Formatting tweaks
[ci-skip]

Change-Id: I49a8b89c47583178a27cec9d8269a2304b3081e3
Signed-off-by: Gari Singh <gari.r.singh@gmail.com>
Signed-off-by: Nick Gaski <ngaski@us.ibm.com>

docs/source/samples.rst

@@ -6,6 +6,19 @@ Hyperledger Fabric Samples
           Please visit the :doc:`prereqs` if you haven't previously installed
           it.
 
+          If you are using Docker Toolbox on Windows 7 or macOS, you
+          will need to use a location under ``C:\Users`` (Windows 7) or
+          ``/Users`` (macOS) when installing and running the samples.
+
+          If you are using Docker for Mac, you will need to use a location
+          under ``/Users``, ``/Volumes``, ``/private``, or ``/tmp``.  To use a different
+          location, please consult the Docker documentation for
+          `file sharing <https://docs.docker.com/docker-for-mac/#file-sharing>`__.
+
+          If you are using Docker for Windows, please consult the Docker
+          documentation for `shared drives <https://docs.docker.com/docker-for-windows/#shared-drives>`__
+          and use a location under one of the shared drives.
+
 Determine a location on your machine where you want to place the Hyperledger
 Fabric samples applications repository and open that in a terminal window. Then,
 execute the following commands: