lib/zsh: exportAll add support for indentation

Allow indenting the output level

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

modules/lib/zsh.nix

@@ -30,5 +30,13 @@ rec {
   # Given an attribute set containing shell variable names and their
   # assignments, this function produces a string containing an export
   # statement for each set entry.
-  exportAll = vars: lib.concatStringsSep "\n" (lib.mapAttrsToList export vars);
+  exportAll =
+    vars:
+    {
+      indent ? "",
+    }:
+    let
+      separator = if indent == "" then "\n" else "\n" + indent;
+    in
+    lib.concatStringsSep separator (lib.mapAttrsToList export vars);
 }