Add API to post or synch data to the backend like odoo community

[Ujeeee]

Hi, love this app, it will be really great if it can connect to self hosted backend.

[bigolewannabe]

A first pass might be the ability to write data to general storage (ie documents) and then detect when that file changes. When that happens reload the app or minimally indicate it won't write until restarted/refreshed. Sync services like nextcloud and synching can take care of the rest.