v0.23.0 Faster builds, vue module support & more

Hi friends!

Ah, another nice release powered by the community!

Changes: v0.22.4..v0.23.0

Highlights:

• Add support for CSS modules in Vue - #508 thanks to @Lyrkan

• Store externals in an array - #495 thanks to @deAtog

• Add Encore.isRuntimeEnvironmentConfigured() - #500 thanks
  to @stof.

• Add the ability to configure watch options - #486 thanks
  to @Kocal

• Enabled cache and parallelism for terser for faster builds -
  #497 thanks to @Kocal