I added them after reading these replies, yes. I usually don't add screenshots because I don't like adding images to the git repository (people don't really want to clone that), and I don't want to use an external CDN for uploading my images.

In this project in particular, I understand that it is important.

Not sure if there are any restrictions keeping you from linking directly from the project readme, but perhaps a separate repo can drive: https://pages.github.com/

Some months ago, before a GitHub update, you could just paste an image while editing a Markdown file and it would be uploaded to their CDN. You could use that link even in other files (e.g. Org files in my case). They changed their upload system and this is not the case anymore.