Dumping all changes required to be done in our website wrt 0.8.0 release.
- fix min spark supported version. 2.4.3 and 3.*
- talk about diff bundles we have (Hudi-spark-bundles) and when to use which one.
- bulk insert row writer.
- migration guide
- doc updates : moving all docs to 0.8.0 dir etc. regular release guide.