It would have to be a plugin rather than a snippet and it should probably either post only on publication, or (maybe better) give the user a popup with the option of posting whenever a resource is saved. Since you have to save to preview, it's common to save a resource repeatedly over a short time and you probably wouldn't want to post in every case.
It should be relatively easy to do, although I'm not sure how best to implement the popup.
A plugin tied to OnDocPublished should be pretty simple, though.
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