Upated to reflect the latest releases

Added text for both 4.2.0-RC1 and 5.1.0-RC1 for the associated releases.

Upated to reflect the latest releases

Added text for both 4.2.0-RC1 and 5.1.0-RC1 for the associated releases.

Updated for the 4.2.0-Beta2 & 5.1.0-Beta Releases

This updates the README to include pointers to the documentation that
are more clear for end users as well as references to the latest
release tags.

Updated for the 4.2.0-Beta2 & 5.1.0-Beta Releases

This updates the README to include pointers to the documentation that
are more clear for end users as well as references to the latest
release tags.