scripts which are editing yaml configuration (e.g. add-availability) right now they take yaml code, transform it in to json, add/edit whats need and transform back to yaml. unfortunately during first transform from yaml to json, what doesn't looks like json is removed, so all comments '#...' or includes '!include' etc... ale lost during this edit.
1. (idealy) do not use yaml > json > yaml conversion, but edit configuration directly in yaml format
2. improve yaml > json > yaml do not remove this things (propably !extends in future as well)
3. maybe use some wrapper around this special entries, before they are transformed to json, that transformation itself will not remove them, and then when transforming back to yaml, remove this wrapper as well