Edit existing skill

[tanujdargan]

Implemented functionality to update an existing skill in the resume using a PUT request to the /resume/skill route. The update is performed based on the index position of the skill, which acts as a unique identifier (ID).

As part of this implementation:

• The route handler was updated to accept a PUT request containing the skill's index and new data.
• Logic was added to locate the skill by its index and update its content accordingly.
• A test case was written in test_pytest.py to verify the functionality, ensuring the skill is correctly updated when a valid request is sent.