[libnotify] docs/notify-send: Add missing --app-name description to manual

[Marco Trevisan <marcotrevi src gnome org>]

commit e05030875e9312de661bd9c3ca461ded09a98eb1
Author: Ben Blain <mail servc eu>
Date:   Wed Mar 3 04:57:18 2021 +0000

    docs/notify-send: Add missing --app-name description to manual

 docs/notify-send.xml | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/docs/notify-send.xml b/docs/notify-send.xml
index fefbf1a..c8eb6ef 100644
--- a/docs/notify-send.xml
+++ b/docs/notify-send.xml
@@ -58,6 +58,12 @@
           <para>Show help and exit.</para>
         </listitem>
       </varlistentry>
+      <varlistentry>
+        <term><option>-a</option>, <option>--app-name</option>=<replaceable>APP_NAME</replaceable></term>
+        <listitem>
+          <para>Specifies the app name for the notification.</para>
+        </listitem>
+      </varlistentry>
       <varlistentry>
         <term><option>-A</option>, 
<option>--action</option>=[<replaceable>NAME</replaceable>=]<replaceable>Text...</replaceable></term>
         <listitem>