readline: fix example

(cherry picked from commit a4a07ba996)

modules/programs/readline.nix

@@ -28,7 +28,9 @@ in
     bindings = mkOption {
       default = {};
       type = types.attrsOf types.str;
-      example = { "\C-h" = "backward-kill-word"; };
+      example = literalExample ''
+        { "\\C-h" = "backward-kill-word"; }
+      '';
       description = "Readline bindings.";
     };
 

tests/modules/programs/readline/using-all-options.nix

@@ -7,9 +7,7 @@ with lib;
     programs.readline = {
       enable = true;
 
-      bindings = {
-        "\C-h" = "backward-kill-word";
-      };
+      bindings = { "\\C-h" = "backward-kill-word"; };
 
       variables = {
         bell-style = "audible";

tests/modules/programs/readline/using-all-options.txt

@@ -4,7 +4,7 @@ $include /etc/inputrc
 set bell-style audible
 set completion-map-case on
 set completion-prefix-display-length 2
-"C-h": backward-kill-word
+"\C-h": backward-kill-word
 $if mode=emacs
 "\e[1~": beginning-of-line
 $endif