I feel like you answered your own question...
Like I get it, but English is fluid and is it really that far to make the assumptive leap from "git" to "github/lab/service", seems pretty clear what they meant (even if it's not completely/technically/um-actually correct because git != github).
Yay it seems I don't have to wear the Dunce hat but also, honestly, I'm not even trying to be pedantic on what counts as "git" here. I'm more annoyed that the contribution calendar is considered inherently "git". I doubt Github can even patent that---it's more a habit-tracker thing.
(Okay there's also `git` in the URL, I noticed, which means whoever made the page had that mental mapping in mind but still...)
I just feel clickbaited that this item is at the top of this forum. I'll stop engaging with this now. Nothing of interest for me here.
When I read contribution graph I assumed it would be a revision history graph of commits and authors.
to be fair, git != github is an important distinction that many fail to grasp. we had a manager who conflated the two, meetings were peppered with things like "do a github pull", "will he be able to log in to the repository on his new machine", "i can't find any good tutorials on setting up a git wiki", etc.