I am using Hibernate in my project.

Usually when we use an open source, License.txt file from the open source (in this case Hibernate) will be provided and added to our project as well.

I am looking for something similar to that. Please let me know where I could find a file like that.

hibernate-<version>/lgpl.txt in the distro

Its also in the Hibernate jar, so theres no reason why you should need to add a useless text file to your project.