feat!: add support to update header based on action name

[npalm]

Name header

Add the option to use the name of the action as an header. By adding

<!-- action-docs-header action="action.yml" -->
<!-- action-docs-header action="action.yml" -->

To the readme.

Migration instruction

Including the name header option is by default enabled which will impact the tocLevel by +1. To avoid a change in tocLevel either disable the includeNameHeader or set the tockLvel.