Inithook to enable TKLBAM

[JedMeister]

Subject says it all... Related to #1192

[JedMeister]

I'm thinking the MVP (minimum viable product) is simply a new bash firstboot script (i.e. in firstboot.d) - perhaps 81tklbam or something?!) that will enable tklbam auto daily backups if the Hub API key is set (in /etc/inithooks.conf) and a new var, e.g. TKLBAM_ENABLED (or similar) - e.g. TKLBAM_ENABLED=true.

Then an extension on that would be to create an interactive inithook. Ideally it would only run if a Hub API key has been set (in 80hub-services). Perhaps the easiest way to do that is touch a file somewhere (perhaps /etc/tklbam/.api-key or /var/lib/tklbam/.api-key-added or /var/lib/inithooks/.hub-enabled or something like that...) when the API key is added (i.e. when 80hub-services runs and is filled in, the file is written). And then test for that file (in 81tklbam) and only ask the question if it exists?!