Use smart apostrophes
    
    Originally, this repo would sometimes use U+0027 APOSTROPHE for
    apostrophes and sometimes use U+2019 RIGHT SINGLE QUOTATION MARK for
    apostrophes. This change makes it always use U+2019 because that’s what
    Unicode recommends.
    
    See:
    
    - https://www.unicode.org/versions/Unicode13.0.0/ch06.pdf#G12411
    - https://www.unicode.org/charts/PDF/U0000.pdf#page=4