Windows support and migration to shared JSON files Edit

This release adds Windows support (thanks to @jmolla31).

It also migrates all the current generators to Terraform JSON notation. NOTE that only those shared features (configuration, providers, variables and outputs) have been migrated, as they benefit from NodeJS ability to merge JSON objects. This feature is essential to execute multiple sub-generators in the same folder.

Quite limited yet, but it is now possible to execute multiple generators at the same time, and in the same folder.

Finally, a new sub-generator to create a resource group has been added.