433Kit is a collection of code and documentation designed to assist you in the connection and usage of RF 433MHz transmit and receive modules to/with your Arduino and Rapberry Pi.
This code doesn't seem to include license, which technically means using/forking it is not allowed. If there's no specific concerns about the license, BSD or MIT might be a good choice.
Adding a license is a simple thing for copyright holder - just declare what license will be used in README.md and add LICENSE file with appropriate license. See for example https://opensource.org/licenses/BSD-3-Clause
This code doesn't seem to include license, which technically means using/forking it is not allowed. If there's no specific concerns about the license, BSD or MIT might be a good choice.
Adding a license is a simple thing for copyright holder - just declare what license will be used in README.md and add
LICENSE
file with appropriate license. See for example https://opensource.org/licenses/BSD-3-Clause