🎨 fix typo in welcome tour (#797)
🎨 fix typo in welcome tour (#797)

closes https://github.com/TryGhost/Ghost/issues/8730
- "and 'about' or 'contact' page" -> "an 'about' or 'contact' page"
kevinansfield/Ghost-Admin,TryGhost/Ghost-Admin,kevinansfield/Ghost-Admin,TryGhost/Ghost-Admin,acburdine/Ghost-Admin,acburdine/Ghost-Admin