Better explain the use of Docker commands on Windows

[gkapfham]

Running Docker is sometimes more difficult on Windows because:

• multiple-line commands do not always work
• environment variables are not consistently the same
• the two aforementioned issues vary depending on the Windows terminal in use

These issues should be clarified!

[gkapfham]

Also, for all operating systems, probably want to add a command that shows how to stop an active docker container based on the identifier number.