In this lab, you’ll get some experience working with subtrees.
This lab requires that you have Internet access and have completed at least the first two steps in Connected Lab 10, where you forked the various split projects of the original calc2 project into your area in GitHub and cloned the super_calc project down to your local system.
$ git subtree add -P sub_docs --squash https://github.com/<your github user id>/sub_docs master
Even though you don’t have much history in this repository, you used the --squash command to compress it. Note that the -P stands for prefix, which is the name your subdirectory gets.
$ ls sub_docs $ git log --oneline
Note that there is only one set of history here because there is only one project effectively—even though we have added a repository as a subproject.
$ cd .. ...