Do we need more than one dataset script for each configuration or a single dataset script that manages everything?


Yes one script can be used to define all the configurations of your dataset. For example it’s common for parallel datasets to have one configuration per language pair, like in flores


This repository can just be a Github repository? Is there a particular structure that needs to be followed by the repository? For example the place where the dataset script needs to be placed, its name, where the dataset itself should reside etc.


It must be a dataset repository on the Hugging Face Dataset Hub, see more information about dataset repository creation here 5. In terms of structure the only requirement is to name the dataset script with the same name as your dataset. Then you can place your data in a separate directory if you want. For example
my_dataset/
├── data/
│   ├── lang1.txt
│   └── lang2.txt
├── README.md
└── my_dataset.py

I hope that helps