Alpakka Kafka 2.0.0

Release notes in the Alpakka Kafka documentation

Teskit

• Embedded Kafka 2.4.0 #1018 by @seglo

Benchmarks

• Record inflight metrics during benchmarks #1014 by @seglo

Documentation

• Release notes 2.0.0 #1019 by @ennru

Build

• sbt 1.3.5 #926 by @ennru
• Build: use improved code style plugins #1013 by @ennru