Add license to repo?

[diamondap]

Your documentation is not displaying at https://pkg.go.dev/github.com/stretchr/stew. Instead, the following message appears:

Documentation not displayed due to license restrictions.

The license policy at https://pkg.go.dev/license-policy shows which licenses are acceptable.

[christian-korneck]

As the repo has a license, but it's just in the wrong file/format I've sent a PR to fix that.
#9

(while the pr is open the api docs can be previewed here