Initial release:
* This project includes minimal data files required by the Python Skyfield library: `de421.bsp`, `deltat.data`, `deltat.preds` and `Leap_Second.dat`.
* It provides a small Python script to download the files from their respective source,
* This script eventually checks if some of the files are expired and skips them (by default),
* Usage documentation is included in the `README.md` file.
* This project code is released under the terms of the MIT License.
Skyfield Library: https://rhodesmill.org/skyfield/
The data files were downloaded on July 26th 2019.
Also added the bare minimum configuration to build a source package.
Updated the README with copyright mentions and a usage example.
Bruno Bord