Featured Image for Pages

In functions.php if you replace this line:

add_theme_support( 'post-thumbnails', array( 'post' ) );

with this:

add_theme_support( 'post-thumbnails' );

You’ll be able to add featured images to pages but you’ll still need to edit the template to display them.

the function that inserts thumbnails is the_post_thumbnail(); look how it’s done in content.php and replicate it in page.php