[FR]: Add Host folders to addon Container

[n0nk]

Is your feature request related to a problem? Please describe.

I am using paperless-ngx Addon on Home Assistant. This creates a new folder in the /-directory named "addon_configs". This folder is containing data for paperless which i want to backup using this rclone addon. Sadly this folder is not mounted within the RClone addon. Therefore i am not able to backup it.

Describe the solution you'd like

It would be nice if i could add this (or any other folder) manually in the configuration.
For example a parameter "local_mounts" taking a list of paths which get mirrored
local_mounts:
- /addon_configs #will be mounted within the addon also to /addon_configs/
or with a syntax like in docker-compose for changing the target mount
local_mounts:
- /addon_configs:/somewhere/else #will be mounted to /somewhere/else in the addon

Describe alternatives you've considered

I tried using symlinks on the host but this also failed due to lack of access from within the addon.

Additional context

Paperless-ngx Addon --> https://github.com/BenoitAnastay/paperless-home-assistant-addon