Add more fields in application form

I’d like to add more fields in application form, in addition to simple resume / cover letter.

For example, transcripts from college, grad school, recommendation letters, etc etc.

It seems like ‘new opening’ is just another WP post.

I’ve also checked your hooks in docs, but can’t find relevant information.

• Job Listing | WP Job Openings
• Customizing templates of your Job Listings | WP Job Openings

How can I customize the application details?