Sometimes you want to commit a subfolder on an arbitrary branch (rather than gh-pages branch) as the root directory
to the gh-pages branch.
You will want to do so when, for example, the files to be published on GitHub Pages are generated by a build system.
This document shows the way to commit a build/gh-pages directory to the gh-pages branch by using Git plumbing commands.
In the following example, Windows PowerShell is used as a shell environment.