nixos/boot/external: fixup typo in generated docs, regenerate docs

nixos/modules/system/boot/loader/external/external.md

@@ -6,7 +6,7 @@ Some users may prefer to create advanced workflows around managing the bootloade
 
 You can replace the built-in bootloader support with your own tooling using the "external" bootloader option.
 
-Imagine you have created a new packaged called FooBoot.
+Imagine you have created a new package called FooBoot.
 FooBoot provides a program at `${pkgs.fooboot}/bin/fooboot-install` which takes the system closure's path as its only argument and configures the system's bootloader.
 
 You can enable FooBoot like this:

nixos/modules/system/boot/loader/external/external.xml

@@ -12,7 +12,7 @@
     tooling using the <quote>external</quote> bootloader option.
   </para>
   <para>
-    Imagine you have created a new packaged called FooBoot. FooBoot
+    Imagine you have created a new package called FooBoot. FooBoot
     provides a program at
     <literal>${pkgs.fooboot}/bin/fooboot-install</literal> which takes
     the system closure’s path as its only argument and configures the
@@ -21,7 +21,7 @@
   <para>
     You can enable FooBoot like this:
   </para>
-  <programlisting language="bash">
+  <programlisting language="nix">
 { pkgs, ... }: {
   boot.loader.external = {
     enable = true;