Added cross-references to NixOS manual

nixos/modules/programs/digitalbitbox/doc.xml

@@ -15,9 +15,9 @@
     installed by setting <literal>programs.digitalbitbox</literal>
     to <literal>true</literal> in a manner similar to
 
-    <programlisting>
-      programs.digitalbitbox.enable = true;
-    </programlisting>
+<programlisting>
+<xref linkend="opt-programs.digitalbitbox.enable"/> = true;
+</programlisting>
 
     and bundles the <literal>digitalbitbox</literal> package (see <xref
       linkend="sec-digitalbitbox-package" />), which contains the
@@ -46,11 +46,11 @@
       <literal>digitalbitbox</literal> package which could be installed
       as follows:
 
-      <programlisting>
-        environment.systemPackages = [
-          pkgs.digitalbitbox
-        ];
-      </programlisting>
+<programlisting>
+<xref linkend="opt-environment.systemPackages"/> = [
+  pkgs.digitalbitbox
+];
+</programlisting>
     </para>
   </section>
 
@@ -62,9 +62,9 @@
       The digitalbitbox hardware package enables the udev rules for
       Digital Bitbox devices and may be installed as follows:
 
-      <programlisting>
-        hardware.digitalbitbox.enable = true;
-      </programlisting>
+<programlisting>
+<xref linkend="opt-hardware.digitalbitbox.enable"/> = true;
+</programlisting>
     </para>
 
     <para>
@@ -72,14 +72,14 @@
       the <literal>udevRule51</literal> and <literal>udevRule52</literal>
       attributes by means of overriding as follows:
 
-      <programlisting>
-        programs.digitalbitbox = {
-          enable = true;
-          package = pkgs.digitalbitbox.override {
-            udevRule51 = "something else";
-          };
-        };
-      </programlisting>
+<programlisting>
+programs.digitalbitbox = {
+  <link linkend="opt-programs.digitalbitbox.enable">enable</link> = true;
+  <link linkend="opt-programs.digitalbitbox.package">package</link> = pkgs.digitalbitbox.override {
+    udevRule51 = "something else";
+  };
+};
+</programlisting>
     </para>
   </section>
 </chapter>

nixos/modules/programs/plotinus.xml

@@ -17,7 +17,7 @@
 <para>To enable Plotinus, add the following to your <filename>configuration.nix</filename>:
 
 <programlisting>
-programs.plotinus.enable = true;
+<xref linkend="opt-programs.plotinus.enable"/> = true;
 </programlisting>
 
 </para>