WIP add heredoc templates; only EOF marker at the moment

example/example.hcl

@@ -28,6 +28,11 @@ resource_1 "strlit1" "strlit2" {
   tpl1   = "prefix-${var.bar}"
   tpl2   = "prefix-${func("bar")}"
   tpl3   = "prefix-${func("nested-${var.bar}")}"
+  tpl4   = <<EOF
+    prefix
+    ${func("foo${ var.bar }")}
+    suffix
+  EOF
 
   nested_resource_1 {
     attr1 = 2