Add descriptions and code for a publication dependency. The DataLad Handbok walkthrough doesn't specify this (yet), but a publication dependency of the github sibling on the github-lfs sibling is required if we want to use a single datalad push --to github command to push both git repo and annexed content. See relevant handbook issue here: https://github.com/datalad-handbook/book/issues/841
Updates:
githubsibling on thegithub-lfssibling is required if we want to use a singledatalad push --to githubcommand to push both git repo and annexed content. See relevant handbook issue here: https://github.com/datalad-handbook/book/issues/841