[Templates] Update documentation + templates code

[helene-nguyen]

Proposed changes

• Update documentation
  • Ensures that all contributors follow a standardized format, making it easier to understand and use the repository
  • Helps new contributors quickly grasp the structure, setup, and best practices
  • Keeps documentation up to date with new features, changes, or deprecated elements
• Update templates code

Related issues

• [Templates] Update documentation and templates #3449

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality using different use cases
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality

Further comments

[flavienSindou]

Some suggestion but It looks good to me. Thank you for this update.

[flavienSindou]

Suggested change

	).strftime("%Y-%m-%d %H:%M:%S")
	).isoformat()

[flavienSindou]

Suggested change

	info_msg = (
	"Sending " + str(len(bundles_sent)) + " stix bundle(s) for worker import"
	)
	info_msg = (
	f"Sending {len(bundles_sent)} stix bundle(s) for worker import"
	)