Create release notes for 1.3

[danuw]

What happened?

Create a PR with updated change log.

I will be using PRs listed here to start https://github.com/Green-Software-Foundation/carbon-aware-sdk/pulls?q=is%3Apr+label%3A1.3+is%3Aclosed

I will need support to ensure nothing was missed from the issues too... (start here - currently can only see one bug I will list too https://github.com/Green-Software-Foundation/carbon-aware-sdk/issues?q=is%3Aissue+label%3A1.3+is%3Aclosed)

Please feel free to add anything missing in the comments...

Code of Conduct

• I agree to follow this project's Code of Conduct

Feature Commitment

• I commit to contributing this feature as a PR and working with the GSF to merge this feature into the Carbon Aware SDK.