Revert "nixos/doc: re-format"

This reverts commit ea6e8775bd. The new
format is not an improvement.

nixos/doc/manual/manual.xml

@@ -11,17 +11,26 @@
  <preface xml:id="preface">
   <title>Preface</title>
   <para>
-   This manual describes how to install, use and extend NixOS, a Linux distribution based on the purely functional package management system Nix.
+   This manual describes how to install, use and extend NixOS, a Linux
+   distribution based on the purely functional package management system Nix.
   </para>
   <para>
-   If you encounter problems, please report them on the <literal
-    xlink:href="https://discourse.nixos.org">Discourse</literal> or on the <link
-    xlink:href="irc://irc.freenode.net/#nixos"> <literal>#nixos</literal> channel on Freenode</link>. Bugs should be reported in <link
-    xlink:href="https://github.com/NixOS/nixpkgs/issues">NixOS’ GitHub issue tracker</link>.
+   If you encounter problems, please report them on the
+   <literal
+    xlink:href="https://discourse.nixos.org">Discourse</literal> or
+   on the <link
+    xlink:href="irc://irc.freenode.net/#nixos">
+   <literal>#nixos</literal> channel on Freenode</link>. Bugs should be
+   reported in
+   <link
+    xlink:href="https://github.com/NixOS/nixpkgs/issues">NixOS’
+   GitHub issue tracker</link>.
   </para>
   <note>
    <para>
-    Commands prefixed with <literal>#</literal> have to be run as root, either requiring to login as root user or temporarily switching to it using <literal>sudo</literal> for example.
+    Commands prefixed with <literal>#</literal> have to be run as root, either
+    requiring to login as root user or temporarily switching to it using
+    <literal>sudo</literal> for example.
    </para>
   </note>
  </preface>