🚨 expand javadocs to be complete to resolve compiler warnings

[ryandens]

Add missing @param Javadoc tags to JibExtensionConfiguration constructors to resolve compiler warnings

Adds @param documentation to both constructors in JibExtensionConfiguration.java to fix incomplete Javadoc compiler warnings. The Project constructor documents the parameter's role and configuration cache implications; the ObjectFactory constructor gets a new Javadoc block explaining its use with alternate jib-like frameworks.

^{Macroscope summarized 73f5657.}