Make our own Manjaro installer

How can we make Manjaro installer being customized with all .config or all configuration else and all packages have been installed in the current running OS ?

The way I read this is:
you want to replace some existing installation of some other variant of Linux with Manjaro
but still keep all the configurations that you did to that system.

Is that what you want?

https://wiki.manjaro.org/index.php/Manjaro-tools