option to install in single user mode

action.yml

@@ -6,6 +6,8 @@ inputs:
     description: 'Installation URL that will contain a script to install Nix.'
   install_options:
     description: 'Additional installer flags passed to the installer script.'
+  single_user:
+    description: 'Install Nix in single-user mode'
   nix_path:
     description: 'Set NIX_PATH environment variable.'
   extra_nix_config:
@@ -23,3 +25,4 @@ runs:
         INPUT_INSTALL_OPTIONS: ${{ inputs.install_options }}
         INPUT_NIX_PATH: ${{ inputs.nix_path }}
         INPUT_EXTRA_NIX_CONFIG: ${{ inputs.extra_nix_config }}
+        INPUT_SINGLE_USER: $${{ inputs.extra_nix_config }}