specified var/run/docker.sock directly to mount it

[hkawa608]

Specified the var/run/docker.sock file clearly instead of the var/run folder for the host mount configurations.

• This file is created as a symbolic link with /Users/${username}/.docker/run/docker.sock in Mac environment.
• With the folder mount configurations, /var/run/docker.sock is also created in a container as a symbolic link with the same path. Users or programs can not access the host's file path from inside a container, they cannot also access the socket file.
• On the other hand, with the file mount configurations, /var/run/docker.sock is created as a genuine file, not a symbolic link. So they can access the socket file.

Fixed #1144

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Testing

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Documentation

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