Support for more file-types

Done

Would be great to have this. Also, all files except PDF are lost when importing from ENEX files (this perhaps should be a different vote item).

I'm not sure if you're still interested in feedback on other types in this particular suggestion, but, yes, I'd like other types as well. I filed a new suggestion instead: https://www.amplenote.com/suggested_features/142

Please check out all of the supported file types added in the meantime and let us know if you need any other files explicitly: https://www.amplenote.com/help/attachments