Where do you write code examples?

I'm starting my blog over at https://konradmatej.hashnode.dev/ and I've been writing some React code examples for a post. I've been doing it in my code editor as of now, but I do get a lot of errors due to package.json is not being setup.

I was thinking of setting up an example project to write this code samples.

Do you guys have any suggestions? Do you use any tools?