Adding HTML tags ins and del

Github does not support the `<u>` tag for underlined text, in HTML there exists the tag `<ins>`. On https://www.w3schools.com/tags/tag_ins.asp is written:
The `<ins>` tag defines a text that has been inserted into a document.
Browsers will normally strike a line through deleted text and underline inserted text.

Most browsers will display the `<ins>` element with the following default values:
```
ins {
  text-decoration: underline;
}
```

analogous there exists the tag `<del>` (https://www.w3schools.com/tags/tag_del.asp):
The `<del>` tag defines text that has been deleted from a document.
Browsers will normally strike a line through deleted text and underline inserted text.

Most browsers will display the `<del>` element with the following default values:
```
del {
  text-decoration: line-through;
}
```

Definitions analogue to the underline and strike through tag the implementation for the other formats has been chosen.

1 files changed, 13 insertions, 0 deletions

diff --git a/testing/086/086__style__tags_8h.xml b/testing/086/086__style__tags_8h.xml
new file mode 100644
index 0000000..a1803da
--- /dev/null
+++ b/testing/086/086__style__tags_8h.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<doxygen xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="compound.xsd" version="">
+  <compounddef id="086__style__tags_8h" kind="file" language="C++">
+    <compoundname>086_style_tags.h</compoundname>
+    <briefdescription>
+    </briefdescription>
+    <detaileddescription>
+      <para>In the following the word tag has the style as indicated before it.<itemizedlist><listitem><para>This is a bold <bold>tag</bold>.</para></listitem><listitem><para>This is a <computeroutput>strong</computeroutput> bold <bold>tag</bold>.</para></listitem><listitem><para>This is an italic <emphasis>tag</emphasis>.</para></listitem><listitem><para>This is an <computeroutput>em</computeroutput> italic <emphasis>tag</emphasis>.</para></listitem><listitem><para>This is a strike through <strike>tag</strike>.</para></listitem><listitem><para>This is an underline <underline>tag</underline>.</para></listitem><listitem><para>This is an insterted <ins>tag</ins>.</para></listitem><listitem><para>This is a deleted <del>tag</del>.</para></listitem><listitem><para>This is a typewriter <computeroutput>tag</computeroutput>. </para></listitem></itemizedlist>
+</para>
+    </detaileddescription>
+    <location file="086_style_tags.h"/>
+  </compounddef>
+</doxygen>