Update README and list compatibility with Gradle

Same functionality as previous release.

Compatibility with Gradle 8.x (fixed plugin portal issue)

Redone to allow plugin portal operation to succeed

Compatibility with Gradle 8.x (redone to fix reckon plugin issue)

Release 3.0.4 failed to process the plugin portal release due to an issue with the reckon plugin.

This patch hopefully solved the release problem.

Compatibility with Gradle 8.x

Contribution from community to improve Gradle 8.x compatibility.