message: Fix sourceparagraph:BooleanField
  the function is called `visit_boolean`, not `visit_bool`.
  I wish there was a better way to do this.
diff: @@ -361,7 +361,7 @@ namespace vcpkg
  using type = bool;
  StringView type_name() { return "a boolean"; }
  - Optional<bool> visit_bool(Json::Reader&, StringView, bool b) { return b; }
  + Optional<bool> visit_boolean(Json::Reader&, StringView, bool b) { return b; }
  };
  enum class AllowEmpty : bool
  