Allow for follow mode when reading docker logs

[Kraust]

I noticed that the main container info buffer automatically updates perodically, but the docker logs buffer that you can open with < does not. This tool would be even better if follow mode (e.g. from docker logs -f) would be added as a configuration parameter of some kind

[vlcinsky]

Consider using only follow mode.

If a need for multiple modes arise, we shall account for multiple versions of keybindings.

Currently we have < for logs. Assuming we would use l (lowercase L), we would get e.g.:

• ll: standard logs (get what is known at the moment and stop)
• lf: get logs and follow
• etc.

This relates to #19 (Proposal of alternative key mappings)