added overlay packages, added go overlay

needed go overlay for diffnav

flake.nix

@@ -12,6 +12,7 @@
       inputs.nixpkgs.follows = "nixpkgs";
     };
     rust-overlay.url = "github:oxalica/rust-overlay";
+    go-overlay.url = "github:purpleclay/go-overlay";
     aagl = {
       url = "github:ezKEa/aagl-gtk-on-nix";
       inputs.nixpkgs.follows = "nixpkgs";
@@ -29,6 +30,7 @@
     darwin,
     home-manager,
     rust-overlay,
+    go-overlay,
     aagl,
     swaytreesave,
     vintage-story,
@@ -43,6 +45,7 @@
     myOverlays = { ... }: {
       nixpkgs.overlays = [
         rust-overlay.overlays.default
+        go-overlay.overlays.default
         aagl.overlays.default
         self.common.overlays
       ];
@@ -203,6 +206,7 @@
         {
           nixpkgs.overlays = [
             rust-overlay.overlays.default
+            go-overlay.overlays.default
             self.common.overlays
           ];
         }