Fix a few links.

* fix `/versions/` link
* add missing trailing slashes
* fix a couple of redirects

site/_includes/docs-navbar.html

@@ -15,13 +15,13 @@
         <a class="nav-link {% if page.title == "Examples" %}active{% endif %}" href="{{ site.baseurl }}/docs/{{ site.docs_version }}/examples/" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Examples');">Examples</a>
       </li>
       <li class="nav-item">
-        <a class="nav-link" href="{{ site.themes }}" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Themes');" target="_blank" rel="noopener">Themes</a>
+        <a class="nav-link" href="{{ site.themes }}/" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Themes');" target="_blank" rel="noopener">Themes</a>
       </li>
       <li class="nav-item">
-        <a class="nav-link" href="{{ site.expo }}" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Expo');" target="_blank" rel="noopener">Expo</a>
+        <a class="nav-link" href="{{ site.expo }}/" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Expo');" target="_blank" rel="noopener">Expo</a>
       </li>
       <li class="nav-item">
-        <a class="nav-link" href="{{ site.blog }}" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Blog');" target="_blank" rel="noopener">Blog</a>
+        <a class="nav-link" href="{{ site.blog }}/" onclick="ga('send', 'event', 'Navbar', 'Community links', 'Blog');" target="_blank" rel="noopener">Blog</a>
       </li>
     </ul>
   </div>
@@ -39,7 +39,7 @@
         <a class="dropdown-item" href="https://getbootstrap.com/docs/3.3/">v3.3.7</a>
         <a class="dropdown-item" href="https://getbootstrap.com/2.3.2/">v2.3.2</a>
         <div class="dropdown-divider"></div>
-        <a class="dropdown-item" href="https://getbootstrap.com/docs/versions/">All versions</a>
+        <a class="dropdown-item" href="{{ site.baseurl }}/docs/versions/">All versions</a>
       </div>
     </li>
 
@@ -54,7 +54,7 @@
       </a>
     </li>
     <li class="nav-item">
-      <a class="nav-link p-2" href="{{ site.slack }}" target="_blank" rel="noopener" aria-label="Slack">
+      <a class="nav-link p-2" href="{{ site.slack }}/" target="_blank" rel="noopener" aria-label="Slack">
         {%- include icons/slack.svg class="navbar-nav-svg" -%}
       </a>
     </li>

site/docs/4.1/about/overview.md

@@ -16,7 +16,7 @@ Bootstrap is maintained by a [small team of developers](https://github.com/orgs/
 
 Originally created by a designer and a developer at Twitter, Bootstrap has become one of the most popular front-end frameworks and open source projects in the world.
 
-Bootstrap was created at Twitter in mid-2010 by [@mdo](https://twitter.com/mdo) and [@fat](https://twitter.com/fat). Prior to being an open-sourced framework, Bootstrap was known as _Twitter Blueprint_. A few months into development, Twitter held its [first Hack Week](https://blog.twitter.com/2010/hack-week) and the project exploded as developers of all skill levels jumped in without any external guidance. It served as the style guide for internal tools development at the company for over a year before its public release, and continues to do so today.
+Bootstrap was created at Twitter in mid-2010 by [@mdo](https://twitter.com/mdo) and [@fat](https://twitter.com/fat). Prior to being an open-sourced framework, Bootstrap was known as _Twitter Blueprint_. A few months into development, Twitter held its [first Hack Week](https://blog.twitter.com/engineering/en_us/a/2010/hack-week.html) and the project exploded as developers of all skill levels jumped in without any external guidance. It served as the style guide for internal tools development at the company for over a year before its public release, and continues to do so today.
 
 Originally [released](https://blog.twitter.com/developer/en_us/a/2011/bootstrap-twitter.html) on <time datetime="2011-08-19 11:25">Friday, August 19, 2011</time>, we've since had over [twenty releases]({{ site.repo }}/releases), including two major rewrites with v2 and v3. With Bootstrap 2, we added responsive functionality to the entire framework as an optional stylesheet. Building on that with Bootstrap 3, we rewrote the library once more to make it responsive by default with a mobile first approach.
 

site/docs/4.1/getting-started/introduction.md

@@ -136,10 +136,10 @@ For improved cross-browser rendering, we use [Reboot]({{ site.baseurl }}/docs/{{
 Stay up to date on the development of Bootstrap and reach out to the community with these helpful resources.
 
 - Follow [@getbootstrap on Twitter](https://twitter.com/getbootstrap).
-- Read and subscribe to [The Official Bootstrap Blog]({{ site.blog }}).
-- Join [the official Slack room]({{ site.slack }}).
+- Read and subscribe to [The Official Bootstrap Blog]({{ site.blog }}/).
+- Join [the official Slack room]({{ site.slack }}/).
 - Chat with fellow Bootstrappers in IRC. On the `irc.freenode.net` server, in the `##bootstrap` channel.
 - Implementation help may be found at Stack Overflow (tagged [`bootstrap-4`](https://stackoverflow.com/questions/tagged/bootstrap-4)).
-- Developers should use the keyword `bootstrap` on packages which modify or add to the functionality of Bootstrap when distributing through [npm](https://www.npmjs.com/browse/keyword/bootstrap) or similar delivery mechanisms for maximum discoverability.
+- Developers should use the keyword `bootstrap` on packages which modify or add to the functionality of Bootstrap when distributing through [npm](https://www.npmjs.com/search?q=keywords:bootstrap) or similar delivery mechanisms for maximum discoverability.
 
 You can also follow [@getbootstrap on Twitter](https://twitter.com/getbootstrap) for the latest gossip and awesome music videos.

site/index.html

@@ -78,6 +78,6 @@ gem install bootstrap -v {{ site.current_ruby_version }}
     </p>
     <img class="img-fluid mt-3 mx-auto" src="{{ site.baseurl }}/docs/{{ site.docs_version }}/assets/img/bootstrap-themes.png" alt="Bootstrap Themes" width="1024" height="388">
     <hr class="half-rule">
-    <a href="{{ site.themes }}" class="btn btn-outline-primary">Browse themes</a>
+    <a href="{{ site.themes }}/" class="btn btn-outline-primary">Browse themes</a>
   </div>
 </div>