Looks to me like you were just missing an ! in this line:
automation split: include_dir_list ./automations/
Here’s how I do it:
automation: !include automations.yaml
automation old: !include_dir_merge_list automations
Create a folder called automations and you can put as many separate YAML files in there as you want — and even arrange into sub-folders if it helps. Each of those files should not contain the automation: header. For example, this is my automations/lights/garage-off.yaml:
- alias: Lights - garage light off
description: Turns the garage light off 60s after last motion
id: c2e7f032-9b81-11eb-a9b3-0242ac130003
trigger:
- platform: state
entity_id: binary_sensor.garage_motion
to: 'off'
for:
seconds: 60
condition:
- condition: state
entity_id: light.garage_light
state: 'on'
action:
- service: light.turn_off
entity_id: light.garage_light