How to have attachment option for all the HR transactions such as Promotion, Salary Changes, Termina

Summary

As part of our requirement we wanted to attach a file for all the HR transactions listed below under issue description, Can you please suggest how can we achieve this requirement

Content

One of our requirement is to have an option to attach a file for all the HR transactions such as Promotion transaction , Salary Increment transaction, Termination transaction, Transfer transaction, Temporary Assignment transaction. An this attached file should be available to all the approvers who are part of the approval flow for all these transaction. Can you please suggest how can we achieve this requirement, Many thanks for your suggestions and replies.