nixos/doc: Small updates about wireless configuration. (#55918)

* Reference networking section from installation
* Add info about pskRaw option in networking.wireless.networks

nixos/doc/manual/configuration/wireless.xml

@@ -36,8 +36,25 @@
  </para>
 
  <para>
-  If you are using WPA2 the <command>wpa_passphrase</command> tool might be
-  useful to generate the <literal>wpa_supplicant.conf</literal>.
+  If you are using WPA2 you can generate pskRaw key using
+  <command>wpa_passphrase</command>:
+<screen>
+$ wpa_passphrase ESSID PSK
+network={
+        ssid="echelon"
+        #psk="abcdefgh"
+        psk=dca6d6ed41f4ab5a984c9f55f6f66d4efdc720ebf66959810f4329bb391c5435
+}
+</screen>
+<programlisting>
+<xref linkend="opt-networking.wireless.networks"/> = {
+  echelon = {
+    pskRaw = "dca6d6ed41f4ab5a984c9f55f6f66d4efdc720ebf66959810f4329bb391c5435";
+  };
+}
+</programlisting>
+  or you can use it to directly generate the
+  <literal>wpa_supplicant.conf</literal>:
 <screen>
 # wpa_passphrase ESSID PSK > /etc/wpa_supplicant.conf</screen>
   After you have edited the <literal>wpa_supplicant.conf</literal>, you need to

nixos/doc/manual/installation/installing.xml

@@ -377,6 +377,10 @@
      option can be set to <literal>true</literal> to automatically add them to
      the grub menu.
     </para>
+    <para>
+     If you need to configure networking for your machine the configuration
+     options are described in <xref linkend="sec-networking"/>.
+    </para>
     <para>
      Another critical option is <option>fileSystems</option>, specifying the
      file systems that need to be mounted by NixOS. However, you typically