Maintenance: add Middy license to repository notice

[saragerion]

What were you searching in the docs?

As @dreamorosi correctly described in this PR, we resolved to temporarily importing the middy types

This workaround is not the best solution. It's supposed to be temporary and will be removed and replaced with a better solution with v2, where we will restore the middy core import.

Other than that, we should credit Middy in our license notice.

Is this related to an existing documentation section?

https://github.com/awslabs/aws-lambda-powertools-typescript/blob/main/LICENSE-THIRD-PARTY

How can we improve?

N/A

Got a suggestion in mind?

N/A

Acknowledgment

• I understand the final update might be different from my proposed suggestion, or refused.