Is there a way to import bulk add Features similar to how you bulk add User Stories?
If you need to bulk add features, you can do this from the Feature page itself. There is an Import/Export option towards the upper right hand corner. I'm including the help page for this option. Please note that this option supports a select number of fields that can be imported. They are listed towards the bottom of the help page under the section Portfolio Item.
We also have a more robust alternative which is the Excel Add-in, which allows the import of more fields including custom fields. While more robust, it does involve the installation of additional software and some configuration. I'm including the help page for this option as well, it includes installation instructions including a link to download the prerequisites.