chore(release): 1.0.0-alpha.28 [skip ci]

# [1.0.0-alpha.28](https://code.podlibre.org/podlibre/castopod/compare/v1.0.0-alpha.27...v1.0.0-alpha.28) (2020-12-07)

### Features

* **rss:** add soundbites according to the podcastindex specs ([6b34617d](https://code.podlibre.org/podlibre/castopod/commit/6b34617d07c70522cb941e96d91d9987493413eb)), closes [#83](https://code.podlibre.org/podlibre/castopod/issues/83)