Improve testing on windows

[pelletier197]

Issue #67 revealed an issue with Windows that was not revealed by current unit tests on Linux, and we're interestingly not revealed by unit tests even when running them on windows.

However, the issue was found when running a generate command using the cli. So I see 3 things that could be done:

• add unit tests for windows in the GitHub actions (and ideally for node 17 as well: right now we test only 16). Make sure the shell used is PowerShell and not bash.
• find a way that jest can run the tests using node version 16. For some reasons, parts covered by the tests were not failing on windows and they should have. (Reader.spec.ts)
• run a generate command as a unit test in the pipeline (and maybe do some asserts). This could be considered an integration test of the cli. This one would have failed on windows if it existed.