add popper.js

public/vendor/popper.js/docs/_includes/example20t-code.html

@@ -0,0 +1,14 @@
+<h2 id="example20" tabindex="0"></h2>
+<p id="example20Title">
+    You can show, hide or toggle a tooltip programmatically:
+</p>
+
+<div id="example10code">
+{% highlight javascript %}
+const instance = new Tooltip(referenceElement, {
+    title: "Hey there",
+    trigger: "click",
+});
+instance.show();
+{% endhighlight %}
+</div>