Moved scripts to the overlay folder to be used as packages

All scripts have been moved to the overlay folder in the top level directory

Overlay is now instantiated per configuration to make use of the host variable

overlay/scripts/nix/fetchfromgh.nix

@@ -0,0 +1,36 @@
+{ pkgs ? import <nixpkgs> { } }:
+
+pkgs.writeShellApplication {
+  name = "fetchfromgh";
+  runtimeInputs = [ pkgs.nix-prefetch-scripts ];
+  text = ''
+      if [ $# -ne 1 ] || ! echo "$1" | grep -qE "[A-Za-z0-9_-]+/[A-Za-z0-9_-]+"; then
+        echo "Usage: fetchfromgh someuser/somerepo"
+        echo "     - i.e. fetchfromgh pagedMov/nixos-config"
+        exit 1
+      fi
+
+    if ! curl -s -o /dev/null -w "%{http_code}" "https://github.com/$1" | grep -q "200"; then
+      echo "Couldn't find that repository, curl returned 404."
+      exit 1
+    fi
+
+      json=$(nix-prefetch-git --quiet "https://github.com/$1")
+
+      url=$(echo "$json" | jq '.url' | tr -d '"')
+      owner=$(echo "$url" | awk -F'/' '{print $(NF-1)}')
+      repo=$(echo "$url" | awk -F'/' '{print $NF}')
+      rev=$(echo "$json" | jq '.rev' | tr -d '"')
+      hash=$(echo "$json" | jq '.hash' | tr -d '"')
+
+      output="\
+      src = pkgs.fetchFromGitHub {
+        owner = \"$owner\";
+        repo = \"$repo\";
+        rev = \"$rev\";
+        hash = \"$hash\";
+      };
+      "
+      echo "$output"
+  '';
+}