docs: standardize license headers

[kevgo]

Add license headers clarifying the copyright of source code files.

Related Issue or Design Document

https://github.com/ory-corp/general/issues/602

Checklist

• I have read the contributing guidelines and signed the CLA.
• I have referenced an issue containing the design document if my change introduces a new feature.
• I have read the security policy.
• I confirm that this pull request does not address a security vulnerability.
  If this pull request addresses a security vulnerability,
  I confirm that I got approval (please contact security@ory.sh) from the maintainers to push the changes.
• I have added tests that prove my fix is effective or that my feature works.
• I have added the necessary documentation within the code base (if appropriate).

[kevgo]

Blocking on shipping ory/cli#239 as a new Ory CLI version.