Remove totaly Tether from documentation + dependencies

docs/components/dropdowns.md

@@ -12,6 +12,12 @@ Dropdowns are toggleable, contextual overlays for displaying lists of links and
 * Will be replaced with the ToC, excluding the "Contents" header
 {:toc}
 
+## Overview
+
+Things to know when using the popover plugin:
+
+- Dropdown rely on the 3rd party library [Popper.js](https://popper.js.org) for positioning. You must include [popper.min.js](https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.8.1/popper.es5.min.js) before bootstrap.js in order for dropdowns to work!
+
 ## Examples
 
 Wrap the dropdown's toggle (your button or link) and the dropdown menu within `.dropdown`, or another element that declares `position: relative;`. Dropdowns can be triggered from `<a>` or `<button>` elements to better fit your potential needs.
@@ -19,7 +25,7 @@ Wrap the dropdown's toggle (your button or link) and the dropdown menu within `.
 {% callout info %}
 ### Dropdown menu accessibility
 
-The [<abbr title="Web Accessibility Initiative">WAI</abbr> <abbr title="Accessible Rich Internet Applications">ARIA</abbr>](https://www.w3.org/TR/wai-aria/) standard defines an actual [`role="menu"` widget](https://www.w3.org/TR/wai-aria/roles#menu), but this is specific to application-like menus which trigger actions or functions. <abbr title="Accessible Rich Internet Applications">ARIA</abbr> menus can only contain menu items, checkbox menu items, radio button menu items, radio button groups, and sub-menus. 
+The [<abbr title="Web Accessibility Initiative">WAI</abbr> <abbr title="Accessible Rich Internet Applications">ARIA</abbr>](https://www.w3.org/TR/wai-aria/) standard defines an actual [`role="menu"` widget](https://www.w3.org/TR/wai-aria/roles#menu), but this is specific to application-like menus which trigger actions or functions. <abbr title="Accessible Rich Internet Applications">ARIA</abbr> menus can only contain menu items, checkbox menu items, radio button menu items, radio button groups, and sub-menus.
 
 Bootstrap's dropdowns, on the other hand, are designed to be generic and applicable to a variety of situations and markup structures. For instance, it is possible to create dropdowns that contain additional inputs and form controls, such as search fields or login forms. For this reason, Bootstrap does not expect (nor automatically add) any of the `role` and `aria-` attributes required for true <abbr title="Accessible Rich Internet Applications">ARIA</abbr> menus. Authors will have to include these more specific attributes themselves.
 
@@ -527,7 +533,35 @@ Regardless of whether you call your dropdown via JavaScript or instead use the d
 
 ### Options
 
-*None.*
+Options can be passed via data attributes or JavaScript. For data attributes, append the option name to `data-`, as in `data-placement=""`.
+
+<table class="table table-bordered table-striped table-responsive">
+  <thead>
+    <tr>
+      <th style="width: 100px;">Name</th>
+      <th style="width: 100px;">Type</th>
+      <th style="width: 50px;">Default</th>
+      <th>Description</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>placement</td>
+      <td>string | function</td>
+      <td>'bottom'</td>
+      <td>
+        <p>How to position the popover - top | bottom.</p>
+        <p>When a function is used to determine the placement, it is called with the popover DOM node as its first argument and the triggering element DOM node as its second. The <code>this</code> context is set to the dropdown instance.</p>
+      </td>
+    </tr>
+    <tr>
+      <td>offset</td>
+      <td>number | string</td>
+      <td>0</td>
+      <td>Offset of the dropdown relative to its target. For more information refer to Popper.js's <a href="https://popper.js.org/popper-documentation.html#modifiers..offset.offset">offset docs</a>.</td>
+    </tr>
+  </tbody>
+</table>
 
 ### Methods