man: add required <title>

man/cgroup-sandboxing.xml

@@ -6,6 +6,7 @@
 -->
 
 <refsect1>
+  <title/>
 
 <para id="singular">This option cannot be bypassed by prefixing <literal>+</literal> to the executable path
 in the service unit, as it applies to the whole control group.</para>

man/standard-conf.xml

@@ -8,6 +8,8 @@
 -->
 
 <refsection>
+  <title/>
+
   <refsection id='confd'>
     <title>Configuration Directories and Precedence</title>
 

man/supported-controllers.xml

@@ -6,6 +6,7 @@
 -->
 
 <refsect1>
+  <title/>
 
 <para id="controllers-text">The following controller names may be specified: <option>cpu</option>, <option>cpuacct</option>,
 <option>cpuset</option>, <option>io</option>, <option>blkio</option>, <option>memory</option>, <option>devices</option>,

man/tc.xml

@@ -6,6 +6,8 @@
 -->
 
 <refsect1>
+  <title/>
+
   <variablelist class='network-directives'>
     <varlistentry id='qdisc-parent'>
       <term><varname>Parent=</varname></term>

man/threads-aware.xml

@@ -4,6 +4,7 @@
 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
 
 <refsect1>
+  <title/>
 
 <para id="strict">All functions listed here are thread-agnostic and only a single specific thread may operate on a
 given object during its entire lifetime. It's safe to allocate multiple independent objects and use each from a

man/version-info.xml

@@ -4,6 +4,8 @@
 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
 
 <refsect1>
+  <title/>
+
   <para id="v183">Added in version 183.</para>
   <para id="v184">Added in version 184.</para>
   <para id="v185">Added in version 185.</para>