Onshape provides the ability to import any file type into an existing document. After the import, these appear as tabs at the bottom of the user interface just like part studios and assemblies.
OneIPM now provides support for these imported files. As seen in the screenshot, all imported files will be displayed when browsing into a document within OneIPM, right alongside parts and assemblies. You can right-click on any tile and choose to go directly to that imported file inside of Onshape, add (associate) a task to it, or download the original file to your local computer.
Additionally, when switching to list/detail view, you can double-click on any property of the imported file to change it. This includes being able to rename the file.