[Chore] Fix overlay

Problem: In my recent PR(#264), I accidentally picked overlay output
changes from the philtaken/nixos-vm-tests branch, which broke existing
overlay imports after updating the deploy-rs input.

Solution: Add backwards compatibility so that users don't have to make
changes to their nix flakes.

1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index 49b993a..672db8f 100644
--- a/README.md
+++ b/README.md
@@ -99,7 +99,7 @@ In the above configuration, `deploy-rs` is built from the flake, not from nixpkg
     deployPkgs = import nixpkgs {
       inherit system;
       overlays = [
-        deploy-rs.overlay
+        deploy-rs.overlay # or deploy-rs.overlays.default
         (self: super: { deploy-rs = { inherit (pkgs) deploy-rs; lib = super.deploy-rs.lib; }; })
       ];
     };