Add some doc comments

microsoft/surface/surface-pro-intel/default.nix

@@ -1,5 +1,9 @@
 { lib, ... }:
 
+# This module is intended to support the Surface Pro range, specifically those with Intel CPUs.
+# It's expected it will work equally well on many other Surface models, but they may need further
+# config changes to work well.
+
 let
   inherit (lib) mkDefault;
 in {
@@ -7,6 +11,7 @@ in {
     ../common
     ../../../common/pc
     ../../../common/pc/ssd
+    # The Intel CPU module auto-includes Intel's GPU:
     ../../../common/cpu/intel
   ];