README updates for 2.0.0 release
README updates for 2.0.0 release

This patch updates the README for the 2.0.0 release and performs some editing / cleanup.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #84 from JoshRosen/readme-updates.

devfreesg/spark-avro,CrazyJacky/spark-avro,tresata-opensource/spark-avro,databricks/spark-avro,fvlankvelt/spark-avro,tresata-opensource/spark-avro,fvlankvelt/spark-avro,devfreesg/spark-avro,databricks/spark-avro,CrazyJacky/spark-avro