Improves example of CArray and explanation of methods.
Improves example of CArray and explanation of methods.

Closes #3146

perl6/doc,MasterDuke17/doc,MasterDuke17/doc,tbrowder/doc,perl6/doc,perl6/doc,tbrowder/doc,tbrowder/doc,perl6/doc,tbrowder/doc,perl6/doc,MasterDuke17/doc,MasterDuke17/doc