v2.4.0

Added

• 3CH speaks French. A language menu in the top bar switches between
  English and Français. It changes the themes, the interface and the
  voice, and 3CH remembers your choice. On the first launch it follows the
  language of your system. Switching keeps the same theme in the other
  language, and bringing back a subject from the history switches the language
  when it needs to.
• Six French themes: Chimère, Constructeur, Darwin, Fantasy, Action
  hollywoodienne and Urbain, with their sentence shapes rewritten for French.
  Words agree like in real French ("une sorcière verte", "des yeux verts"),
  and the sentence is fixed up afterwards: "le arbre" becomes "l'arbre", "de le"
  becomes "du", "à les" becomes "aux".
• The robot voice speaks French. The subject is read in the language of its
  theme, with a voice of that language when the system has one. The timer
  voice has its own French lines, with the same passive-aggressive tone.
• Themes can say their language ("lang") and link words so that adjectives and
  articles agree with the noun ({being#a}, {adj@a}, [un|une@a]). See
  app/README.md.
• npm run sample -- themes/x.json validates a theme and prints sample
  subjects for every structure, to proofread a theme you write.

Changed

• The whole interface, the dialogs and the notifications follow the language.
• For French speech on Windows, install a French voice (Settings, Time &
  language, Speech). Without one, the default voice reads the French text. On
  macOS, 3CH picks a French voice from the ones installed.