add example to defaultTo
add example to defaultTo

This is to clarify that some falsey values are allowed through.  I realize that the reader can deduce that, but this simple example might be a flag to the uninitiated that this isn't a falsey check.
ramda/ramda,davidchambers/ramda,CrossEye/ramda,Bradcomp/ramda,ramda/ramda,davidchambers/ramda,Bradcomp/ramda,CrossEye/ramda,CrossEye/ramda,ramda/ramda