Sometimes I just love how the open source community works nowadays! Sometimes you use your favourite search engine to find a package/repository/etc..., just to find out thatit contains a quickstart info, a proper package.json or docker-compose.yml. All you need to do is "npm install && npm run" or "docker-compose build && docker-compose up" and you are good to go.
This helps devs to contribute to open source software soooooo much!
TL;DR: Use Docker, package.json, requirements.txt, and for the love of god, write a Quickstart section into your Readme!