man: Add missing <literal> tags in various man pages

A minor formatting improvement brought to you by the wonders of `git
grep`.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

man/systemctl.xml

@@ -1341,7 +1341,7 @@ Jan 12 10:46:45 example.com bluetoothd[8900]: gatt-time-server: Input/output err
                   </row>
                   <row>
                     <entry><literal>indirect</literal></entry>
-                    <entry>The unit file itself is not enabled, but it has a non-empty <varname>Also=</varname> setting in the <literal>[Install]</literal> unit file section, listing other unit files that might be enabled, or it has an alias under a different name through a symlink that is not specified in Also=. For template unit file, an instance different than the one specified in <varname>DefaultInstance=</varname> is enabled.</entry>
+                    <entry>The unit file itself is not enabled, but it has a non-empty <varname>Also=</varname> setting in the <literal>[Install]</literal> unit file section, listing other unit files that might be enabled, or it has an alias under a different name through a symlink that is not specified in <varname>Also=</varname>. For template unit file, an instance different than the one specified in <varname>DefaultInstance=</varname> is enabled.</entry>
                     <entry>0</entry>
                   </row>
                   <row>

man/systemd.automount.xml

@@ -35,9 +35,9 @@
     this unit type. See
     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for the common options of all unit configuration files. The common
-    configuration items are configured in the generic [Unit] and
+    configuration items are configured in the generic <literal>[Unit]</literal> and
-    [Install] sections. The automount specific configuration options
+    <literal>[Install]</literal> sections. The automount specific configuration options
-    are configured in the [Automount] section.</para>
+    are configured in the <literal>[Automount]</literal> section.</para>
 
     <para>Automount units must be named after the automount directories they control. Example: the automount point
     <filename noindex='true'>/home/lennart</filename> must be configured in a unit file

man/systemd.mount.xml

@@ -34,9 +34,9 @@
     this unit type. See
     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for the common options of all unit configuration files. The common
-    configuration items are configured in the generic [Unit] and
+    configuration items are configured in the generic <literal>[Unit]</literal> and
-    [Install] sections. The mount specific configuration options are
+    <literal>[Install]</literal> sections. The mount specific configuration options are
-    configured in the [Mount] section.</para>
+    configured in the <literal>[Mount]</literal> section.</para>
 
     <para>Additional options are listed in
     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

man/systemd.path.xml

@@ -34,9 +34,9 @@
     this unit type. See
     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for the common options of all unit configuration files. The common
-    configuration items are configured in the generic [Unit] and
+    configuration items are configured in the generic <literal>[Unit]</literal> and
-    [Install] sections. The path specific configuration options are
+    <literal>[Install]</literal> sections. The path specific configuration options are
-    configured in the [Path] section.</para>
+    configured in the <literal>[Path]</literal> section.</para>
 
     <para>For each path file, a matching unit file must exist,
     describing the unit to activate when the path changes. By default,

man/systemd.slice.xml

@@ -55,9 +55,9 @@
     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for the common options of all unit configuration
     files. The common configuration items are configured
-    in the generic [Unit] and [Install] sections. The
+    in the generic <literal>[Unit]</literal> and <literal>[Install]</literal> sections. The
     slice specific configuration options are configured in
-    the [Slice] section. Currently, only generic resource control settings
+    the <literal>[Slice]</literal> section. Currently, only generic resource control settings
     as described in
     <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry> are allowed.
     </para>

man/systemd.socket.xml

@@ -35,9 +35,9 @@
     this unit type. See
     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for the common options of all unit configuration files. The common
-    configuration items are configured in the generic [Unit] and
+    configuration items are configured in the generic <literal>[Unit]</literal> and
-    [Install] sections. The socket specific configuration options are
+    <literal>[Install]</literal> sections. The socket specific configuration options are
-    configured in the [Socket] section.</para>
+    configured in the <literal>[Socket]</literal> section.</para>
 
     <para>Additional options are listed in
     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

man/systemd.swap.xml

@@ -37,9 +37,9 @@
     this unit type. See
     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for the common options of all unit configuration files. The common
-    configuration items are configured in the generic [Unit] and
+    configuration items are configured in the generic <literal>[Unit]</literal> and
-    [Install] sections. The swap specific configuration options are
+    <literal>[Install]</literal> sections. The swap specific configuration options are
-    configured in the [Swap] section.</para>
+    configured in the <literal>[Swap]</literal> section.</para>
 
     <para>Additional options are listed in
     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

man/systemd.target.xml

@@ -34,8 +34,8 @@
     <para>This unit type has no specific options. See
     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for the common options of all unit configuration files. The common
-    configuration items are configured in the generic [Unit] and
+    configuration items are configured in the generic <literal>[Unit]</literal> and
-    [Install] sections. A separate [Target] section does not exist,
+    <literal>[Install]</literal> sections. A separate <literal>[Target]</literal> section does not exist,
     since no target-specific options may be configured.</para>
 
     <para>Target units do not offer any additional functionality on

man/systemd.timer.xml

@@ -35,9 +35,9 @@
     this unit type. See
     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for the common options of all unit configuration files. The common
-    configuration items are configured in the generic [Unit] and
+    configuration items are configured in the generic <literal>[Unit]</literal> and
-    [Install] sections. The timer specific configuration options are
+    <literal>[Install]</literal> sections. The timer specific configuration options are
-    configured in the [Timer] section.</para>
+    configured in the <literal>[Timer]</literal> section.</para>
 
     <para>For each timer file, a matching unit file must exist,
     describing the unit to activate when the timer elapses. By