message: Bump changelog.
  Original commit:
diff: +# Next Release
  +
  +# Enso 2.0.0-alpha.8 (2021-06-09)
  +
  +<br/>![New Features](/docs/assets/tags/new_features.svg)
  +
  +#### Enso Compiler
  +
  +- [Updated Enso engine to version 0.2.12][1640]. If you're interested in the
  + enhancements and fixes made to the Enso compiler, you can find out more
  + details in
  + [the engine release notes](https://github.com/enso-org/enso/blob/main/RELEASES.md).
  +
  +[1640]: https://github.com/enso-org/ide/pull/1664
  +
  +<br/>
  +
  # Enso 2.0.0-alpha.7 (2021-06-06)
  <br/>![New Features](/docs/assets/tags/new_features.svg)
  