add object to list button script in inspector?

sorry if the title is vague, allow me to explain myself. I am trying to make a script that can be reused in other projects without the requirement of hard coding.

Basically, lets say i have a script with a list that is empty, and through the inspector i go to the object that carries this script, at the script, i would need something like "Add new dialog", when I press on it, I want it to create and empty field which I can fill out with text. And when I playtest it, it should show that text in a dialog window.

That's more or less the idea that I am aiming at. For now, all I need to know is how to create a button for the script that I can press in the inspector to add items to the object containing the script. Also, does this have a specific name?