Header/Footer comments land in wrong places sometimes when injected into a YAML document

[ahuffman]

During injection of header/footer comments, they do not always land where they "should" within the YAML document.

This is due to an issue in upstream go library yaml.v3. The problem is essentially an issue with how/where to handle comments in maps.

The headers will land below the target injection point, and the footers can end up sometimes above the target injection point.

We should make an effort to contribute to the upstream library to solve the problem within the library.

Related to:
go-yaml/yaml#610
go-yaml/yaml#695