chore: Add Taskfile tasks to lint YAML files.

[Bill-hbrhbr]

Description

This PR sets up the basic task configuration files and linting tasks for Yaml files.
Note that for the task file naming convention, lowercase filenames are used, and the suffix .yaml is used. This is consistent with the practice applied in spider.

Additionally:

• Apart from the top-level task file, all helper task files will be placed in the tasks/ directory.
• Yaml attributes that are lists now consistently use hyphens across multiple lines instead of square brackets on one line.

Validation performed

• The linting process for Yaml files completes successfully.

[davidlion]

On top of the comments lets make 2 changes:

1. rename the directory tasks/ to taskfiles/
2. drop the -tasks suffix inside this directory (e.g. rename lint-tasks.yaml to lint.yaml)