Update .spi.yml (#5)

* Update .spi.yml

* Remove plugin

* Update Package.swift

Ks1019/add documentation (#3)

* Add plugin

* Add docs to Script.swift

* Add docs to Script+Comparable.swift

* Add docs to SystemCall.swift

* Fix docc

* Fix

* Fix

* Add docs

* Add docs to Script+Files.swift

* Add docs to Script+String.swift

* Run `swiftlint --fix .`

Release 0.0.1