idea: butler v2 maybe. manager merge=[true,false], group="anothermanager"

[matthsmi]

Currently we manage prometheus main config and rules files in the same manager object with

primary-config & additional files. This is because in butler v0 we wanted to keep the files together/grouped since getting an updated alerts file without the prometheus.yml to support it would be bad.

The approach goes against the grain of the modular multi manager butler v1. the additional-files could be deprecated and prometheus main and rules files could be separated into separate managers with the addition of

merge=[true,false] merge all the files listed under primary-config
group=["anothermanager","yetanothermanager"] allows the grouping together of different manager objects, if one doesnt run, then the other doesnt run.