Include dependabot.yaml as an additional valid name for dependabot

[Sergio Arroutbi]

Is there an existing issue for this?

• I have searched the existing issues

Feature description

According to w3schools:
"Most of the yaml users are using .yaml as their preferred choice."

It would be nice to have 'dependabot.yaml' as an additional valid name for Dependabot (keeping dependabot.yml as the default to run if both exist)

[William Jackson]

dependabot.yaml works just fine right now. I use this filename in all my repositories.

[Sergio Arroutbi]

dependabot.yaml works just fine right now. I use this filename in all my repositories.

Thanks for the update. I will re-check it to see if my particular case is failing due to something else