[Feature] provide flag to supply a setup script while provisioning

Currently we have profiles for snc or to provision the instance as a runner for github, gitlab, which are pre-defined and part of the mapt codebase

In addition to it, it'd be useful if the user while creating the instance could also provide a setup script that runs and sets up the instance as the user wants, specifically i often use the azure windows create command to provision a temporary development/testing machine and i have a script that i run after the instance is provisioned to setup the development environment (install vscode, golang, gnuwin32 etc.) if i could provide the setup script while provision the machine itself, that'd be useful

/cc @adrianriobo