Update for release v21.09.1 (#38)

* Updated the defaults in `common.pkvars.hcl` to use hardware version 19, which provides the best performance and latest features available in ESXi 7.0 U2.
* Updated the Rocky Linux build to use UEFI; however without secure boot.
* Refactored all builds to pass the language, keyboard, and timezone to the configuration files.
* Refactored all builds with input variable definitions separated into `variables.pkr.hcl`.
* Refactored all builds to use `<build>.auto.pkvars.hcl` for input variables the and `<build>.pkr.hcl` for the template configurations, with simplified names for `<build>`.
* Refactored all builds to use `${path.cwd}/output/` as the path for the manifest post-processor.

Updates for release v21.09. (#30)

Updates for release v21.09.

Updates for release v21.08. (#24)

* Release v21.08

Updates for Release v21.08.

* Release v21.08

Updates for Release v21.08.

Merge pull request #23 from rainpole/windows-autounattend-fixup

Simplify Windows Autounattend.xml <DriverPaths/>