message: fix babel config for webpack build
diff: @@ -29,5 +29,9 @@ module.exports = {
  compact: false,
  },
  },
  - plugins: [require.resolve('@babel/plugin-proposal-class-properties')],
  + plugins: [
  + require.resolve('@babel/plugin-proposal-class-properties'),
  + require.resolve('@babel/plugin-proposal-nullish-coalescing-operator'),
  + require.resolve('@babel/plugin-proposal-optional-chaining'),
  + ],
  };
  