Fix confusing descriptions

lib/modules/rclone.nix

@@ -4,9 +4,15 @@ let
   targetName = "rclone";
 
   mkSystemdDependencyOption =
-    { default, ... }: lib.mkOption {
+    { default, global ? false, ... }: lib.mkOption {
       type = lib.types.attrsOf (lib.types.listOf lib.types.str);
-      description = "The systemd services this sync depends on.";
+      description = "The systemd services ${
+          if global then "all" else "this"
+        } sync${
+          if global then "s" else ""
+        } depend${
+          if global then "" else "s"
+        } on.";
       example = {
         secrets = [
           "sops-nix.service"
@@ -110,6 +116,7 @@ in {
 
       systemdDependencies = mkSystemdDependencyOption {
         default = {};
+        global = true;
       };
 
       configs = (builtins.mapAttrs