Add optional task to Install config.yml for specified users

[jasonlearst]

Hello @darkwizard242,

I wanted the ability to specify a custom config.yml for the users of my system. I added an additional task install_config.yml which by default does not run. In order for the task to run 2 new variables need to be defined. I added them to the defaults/main.yml as undefined.

# By default, no config file will be copied (undefined)
# Example: lazydocker_config_src: /path/to/your/config.yml
lazydocker_config_src:
# By default, no users will receive the config (undefined)
# Example:
# lazydocker_users:
#   - user1
#   - user2
lazydocker_users: []

I decided I would create a PR to check if you would be interested to add this feature to the main project. Please let me know if you would like me to make any changes or clarify the changes I have already made.