fluent-bundle 0.13.0 (September 24, 2020)

• Update to fluent-syntax 0.10.
• Add FluentBundle::write_pattern which can write to pre-allocated buffer.
• Get rid of DisplayableNode and simplify FluentValue.
• Reorganize Resolver around impl Write.
• Introduce FluentArgs as a struct over Vec<FluentArg>.
• Introduce FluentMessage and FluentAttributes.
• Make FluentArgs accept Cow<str> as keys.