Bump bootstrap version (dbc-team#1130)

Author: tcbegley

content/docs/themes.md

@@ -39,7 +39,7 @@ See the [available themes](#available-themes) for more.
 Each theme such as is simply a BootstrapCDN URL stored as a string, so using the themes module is really equivalent to doing something like the following.
 
 ```python
-BS = "https://cdn.jsdelivr.net/npm/[email protected].5/dist/css/bootstrap.min.css"
+BS = "https://cdn.jsdelivr.net/npm/[email protected].6/dist/css/bootstrap.min.css"
 app = dash.Dash(external_stylesheets=[BS])
 ```
 

templates/partials/head.html

@@ -3,7 +3,7 @@
 
 <meta charset="utf-8" />
 <meta name="viewport" content="width=device-width, initial-scale=1" />
-<link href="https://cdn.jsdelivr.net/npm/[email protected].5/dist/css/bootstrap.min.css" rel="stylesheet" crossorigin="anonymous" />
+<link href="https://cdn.jsdelivr.net/npm/[email protected].6/dist/css/bootstrap.min.css" rel="stylesheet" crossorigin="anonymous" />
 <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/styles/tomorrow-night-eighties.min.css" />
 <link rel="stylesheet" href="/static/docs.css" />
 <link rel="shortcut icon" type="image/x-icon" href="/static/images/favicon.ico" />

templates/partials/scripts.html

@@ -1,4 +1,4 @@
-<script src="https://cdn.jsdelivr.net/npm/[email protected].5/dist/js/bootstrap.bundle.min.js" crossorigin="anonymous"></script>
+<script src="https://cdn.jsdelivr.net/npm/[email protected].6/dist/js/bootstrap.bundle.min.js" crossorigin="anonymous"></script>
 <script src="/static/js/v2-alert.js"></script>
 <script src="/static/js/highlight.min.js"></script>
 <script>