Add MNIST example (#1)

* example

* add example fix

* add to docs

Author: lockwo

docs/_overrides/bluesky.svg

@@ -0,0 +1,18 @@
+{% import "partials/language.html" as lang with context %}
+<a href="{{ config.repo_url }}" title="{{ lang.t('source.link.title') }}" class="md-source" data-md-component="source">
+  <div class="md-source__icon md-icon">
+    {% set icon = config.theme.icon.repo or "fontawesome/brands/git-alt" %}
+    {% include ".icons/" ~ icon ~ ".svg" %}
+  </div>
+  <div class="md-source__repository">
+    {{ config.repo_name }}
+  </div>
+</a>
+<a href="{{ config.theme.bluesky_url }}" title="Go to Bluesky" class="md-source">
+  <div class="md-source__icon md-icon">
+    {% include "bluesky.svg" %}
+  </div>
+  <div class="md-source__repository">
+    {{ config.theme.bluesky_name }}
+  </div>
+</a>

docs/_overrides/partials/source.html

@@ -3,6 +3,20 @@ html {
     scroll-padding-top: 50px;
 }
 
+/* Fit the Bluesky handle alongside the GitHub one in the top right. */
+div.md-header__source {
+    width: revert;
+    max-width: revert;
+}
+
+a.md-source {
+    display: inline-block;
+}
+
+.md-source__repository {
+    max-width: 100%;
+}
+
 /* Emphasise sections of nav on left hand side */
 nav.md-nav {
   padding-left: 5px;