...users want to be able to save changes and continue editing...what I've done:
- User clicks to edit a page
- User edits some stuff and clicks "Save"
- After a delay "Save" button changes to "Done"
- User clicks "Done"
- User automatically navigates to "Changes successfully published"
There's two problematic scenarios with this approach:
- The user makes edits and is done. The user clicks "SAVE". Waits. Clicks "DONE" and leaves edit page. 
- The user makes edits, is not done but wishes to save edits. Clicks "SAVE" and continues to edit. The user again is not done but wishes to save. Clicks "DONE" and leaves edit page. 
From comments...
I'm worried about having 3 blue buttons in a row "Save / Preview / Done" and make a user focusing more. From the other perspective I'm worried that a user will click "done" without reading
SAVE and DONE having different background/foreground colors helps distinguish one from the other. DONE being the darkest gives it the sense of anchor, or finality. SAVE being a button helps it stand out:
AnotherHowever, another option is to style SAVE similar to PREVIEW, because neither of these two actions leave the form.
The user quickly learns PREVIEW and SAVE are in-edit actions, and DONE is terminal.
 
                 
                
