Request: Swift Package Manager support

[kotarofujita]

Is your feature request related to a problem? Please describe.
I currently can't use PM to download your package. It would be great to get PM support to download this library via Swift PM. When I try

What I see when I try to download from your git repo directly from Xcode:

What I would like to see eventually:

Describe the solution you'd like
While I have not made one myself, I founded this article as a possible start point:
https://www.swiftbysundell.com/articles/managing-dependencies-using-the-swift-package-manager/

My general understanding is that a manifest needs to be made along with some other tweaks.

BTW Thank you so much for making such a useful library. I've used it a lot in the past.

[jinSasaki]

Thanks @kotarofujita
SPM is supported now :) Please after 2.5.1 version.