added packer command for windows image hcl file

Author: ericd-mst-github

articles/virtual-machines/windows/build-image-with-packer.md

@@ -168,6 +168,11 @@ Build the image by opening a cmd prompt and specifying your Packer template file
 ```
 ./packer build windows.json
 ```
+You can also build the image by specifying the *windows.pkr.hcl* file as follows:
+
+```
+packer build windows.pkr.hcl
+```
 
 An example of the output from the preceding commands is as follows: