feature: add support to install os package

[tanmoysrt]

Is your feature request related to a problem? Please describe

Currently, the docker images don't had support for accept input from user to install external os packages.
To do this, users need always to edit the Dockerfile and update the Dockerfile to install os packages, which is not a great user experience.

Describe the solution you'd like

We like to take inspiration from Heroku or other buildpack-based hosting platforms as a solution.
The user can provide the names of the packages in a file Aptfile, and when building the image we will install the os packages.

Additional Context

We can install the packages from AptFile file using this command

test -f AptFile && xargs -a AptFile apt install -yqq || true

We can pass preinstallation commands as well from SetupCommand file using this command

test -f SetupCommand && while read -r cmd; do eval "$cmd"; done < SetupCommand || true

Are you working on this?

Yes

[tanmoysrt]

Fixed all the issues in #56