Add Windows support (#296)

* feat: add platform type

* feat: add windows downloadUrl

* fix: executable file must has a valid extension

* fix: downloadLatest pathForValidation not found in windows

* fix: path format in windows

* fix: downloadVersion url

* style: use ==/!= instead of ===/!==

* fix: use path.sep instead of path.normalize or path.resolve

* fix: replace the hardcoded unix path separators / with `${path.sep}`

* revert: "style: use ==/!= instead of ===/!=="

This reverts commit d5b56b4.

Author: he0119