$ cat << EOT >> notes.txt
To update from a dataset with a shared history, you
need to add this dataset as a sibling to your dataset.
"Adding a sibling" means providing DataLad with info about
the location of a dataset, and a name for it. Afterwards,
a "datalad update --merge -s name" will integrate the changes
made to the sibling into the dataset.
A safe step in between is to do a "datalad update -s name"
and checkout the changes with "git/datalad diff"
to remotes/origin/master

EOT
$ datalad save -m "Add note on adding siblings"
add(ok): notes.txt (file)
save(ok): . (dataset)
action summary:
  add (ok: 1)
  save (ok: 1)
