Outdated egg!
This is an egg for CHICKEN 4, the unsupported old release. You're almost certainly looking for the CHICKEN 5 version of this egg, if it exists.
If it does not exist, there may be equivalent functionality provided by another egg; have a look at the egg index. Otherwise, please consider porting this egg to the current version of CHICKEN.
YAML
There is minimal documentation in README.markdown in the egg.
Source
The source can be found at https://github.com/tenderlove/chicken-yaml .