Add the new finally core flow property to all docs places that need it

[anna-geller]

Description

Once this is merged kestra-io/kestra#6686, we will need to update many places to ensure users are aware of this new core Flow-level property.

• new Workflow Component page
• the Optionally, ... section here https://kestra.io/docs/workflow-components/flow#components-of-a-flow with a link to the new page above
• basic.md that is showing up in the Editor https://github.com/kestra-io/kestra/blob/develop/ui/src/assets/documentations/basic.md
• New video for this for the Workflow Component playlist - cc @wrussell1999 for planning + embed it in the docs page
• Perhaps add one blueprint https://github.com/kestra-io/blueprints with finally showing how to use it for cleanup task with the new Docker Stop task feat: add a Stop task plugin-docker#46