feat: add skillskape dataset

[jjzha]

Link to issue: #22

Description

Added the SkillSkape dataset (https://aclanthology.org/2024.nlp4hr-1.4.pdf). I modified the tasks/ranking/skill_extraction.py file by adding a SkillSkape class and the corresponding test and imports. I was not sure if this is satisfactory, because I did not know whether to add the SkillSkape class in a new file as the task is almost identical to TECH and HOUSE.

If needed, I can split it up. But then would like to know what to call the file (e.g., skill_extraction_skillskape.py?).

Checklist

• Added new tests for new functionality
• Tested locally with example tasks
• Code follows project style guidelines
• Documentation updated
• No new warnings introduced

[Mattdl]

Fits right in with the existing skill extraction datasets. Great work, thanks for contributing!