Docs: Document recommendations for optional `/archive` and `/ocrtemp` volumes

[cmccambridge]

Removed from unRAID templates since they're not required but unRAID generates invalid docker commandlines without a specified mount for every volume in a template.

Should add documentation to the unRAID Integration setting to explain how to add these back in. Also consider adding support within the container to detect mounted vs unmounted /archive share, so that users don't inadvertently archive into the container...