Create awsutils mixin with documentation

Add documentation and provider configuration for awsutils mixin.

Author: goruha

src/mixins/provider-awsutils-no-account-map.mixin.tf

@@ -0,0 +1,10 @@
+# <-- BEGIN DOC -->
+#
+# This mixin is meant to be added to a terraform module that wants to use the awsutils provider.
+# It assumes the standard `providers.tf` file is present in the module.
+#
+# <-- END DOC -->
+
+provider "awsutils" {
+  region = var.region
+}