Allow buttercup-mobile to access pre-existing local vault file [Feature Request]

[kolole]

I have a vault file on my server, that I can share to my phone using Samba. I want to be able to open that local vault file. Using WebDAV, Google Drive, Dropbox, etc, is not preferable to me, when I always have access to my own server/cloud.

Even if the file is not on my server, I want to be able to download the file to my phone, and add the vault file the exact same way as I can with buttercup-desktop. For now, the only way to add a local vault, is to create a new vault, which is then stored on the phone. This is not what I want, I want to open an already made vault file.