Festivity mode

[Paul-Bob]

Feature

Winter is coming! Let’s add a christmas configuration that activates a subtle garland on the navbar.

config.christmas = true

Or perhaps a more flexible option:
config.festive_mode = :christmas

This will allow for potential expansion into other festive modes in the future.

[adrianthedev]

This will be so cool!

I'd go with the second API because we can re-use it.

config.festivity = :christmas
config.festivity = :christmas_2024
config.festivity = :easter
config.festivity = :thanksgiving