Below are instructions on how to create a Drupal Bootstrap based sub-theme.
There are several different variations on how to accomplish this task, but this
topic will focus on the two primarily and most common ways.
Copy over one of the starterkits you have chosen from the
./bootstrap/starterkits folder into sites/all/themes or a respective
Rename the folder to a unique machine readable name. This will be your
sub-theme's "name". For this example and future examples we'll use
Rename ./subtheme/cdn.starterkit or, if using the LESS Starterkit,
./subtheme/less.starterkit to match the folder name and append .info
Open ./subtheme/subtheme.info and change the name, description and any
other properties to suite your needs.
WARNING: Ensure that the .starterkit suffix is
not present on your sub-theme's .info filename. This suffix is simply a stop
gap measure to ensure that the bundled starter kit sub-theme cannot be enabled
or used directly. This helps people unfamiliar with Drupal avoid modifying the
starter kit sub-theme directly and instead forces them to create a new sub-theme
Enable Your New Sub-theme
In your Drupal site, navigate to admin/appearance and click the Enable and set default link next to your newly created sub-theme.