Sensei integration for our Storefront theme. Add the code below to your child themes functions.php file.

storefront-funcitons.php

/*********************
*  Sensei Integration
*********************/

/**
 * Declare that your theme now supports Sensei
 */
add_action( 'after_setup_theme','storefront_sensei_support' );
function storefront_sensei_support () {

    add_theme_support( 'sensei' );

}

/**
 * Remove the default Sensei wrappers
 */
global $woothemes_sensei;
remove_action( 'sensei_before_main_content', array( $woothemes_sensei->frontend, 'sensei_output_content_wrapper' ), 10 );
remove_action( 'sensei_after_main_content', array( $woothemes_sensei->frontend, 'sensei_output_content_wrapper_end' ), 10 );


/**
 * Add The storefront custom  Sensei content  wrappers
 */
add_action('sensei_before_main_content','storefront_sensei_wrapper_start', 10);
add_action('sensei_after_main_content','storefront_sensei_wrapper_end', 10);

function storefront_sensei_wrapper_start (){

    echo '<div id="primary" class="content-area">';
    echo '<div id="main" class="site-main" role="main">';

}

function storefront_sensei_wrapper_end (){

    echo'</div> <!-- end #main -->';
    echo'</div> <!-- end #primary -->';
    get_sidebar();

}

/***************************
*  // END Sensei Integration
****************************/

I just had (yet) another user point out that this doc should probably be modified:
https://docs.woocommerce.com/document/woothemes-storefront/
Here lemme fire it up on mine and recreate the problem, ready?
Course page without this snippet ---> http://prntscr.com/c6jycf
Course page WITH this snippet added ----> http://prntscr.com/c6jzyg

I had the same issue like the example from @BurlesonBrad.

When I add the snippet into the functions.php file of my blank child theme, there is a big empty space on the right side of the page "Courses".