feat: update navigation and footer (#17)

* refactor(layout): move back link to layout

* feat: add concept.svg

* feat(menu): cleanup

* feat(footer): add sitemap

_includes/footer.html

@@ -1,6 +1,13 @@
 <div class="footer">
-    <p align="right">Looking for bitcoin-only meetups? Have a look at <a href="https://bitcoin-only.com/meetups"
-            target="_blank">bitcoin-only.com/meetups</a></p>
-    Made with <a href="https://dergigi.com/support" target="_blank">🧡</a> by <a href="https://dergigi.com"
-        target="_blank">Gigi</a>.
+        <p align="right">
+        {% for page in site.pages %}
+                {% if page.path contains ".md" %}
+                        <a href="{{ page.url }}">{{ page.title }}</a> |
+                {% endif %}
+        {% endfor %}
+
+        Looking for bitcoin-only meetups? Have a look at <a href="https://bitcoin-only.com/meetups"
+                        target="_blank">bitcoin-only.com/meetups</a></p>
+        Made with <a href="https://dergigi.com/support" target="_blank">🧡</a> by <a href="https://dergigi.com"
+                target="_blank">Gigi</a>.
 </div>

_includes/menu.html

@@ -1,12 +1,9 @@
 <div class="row">
     <div class="span8 offset2" style="margin-bottom: 1rem;">
         <center>
-            <a href="/">Map</a> | 
-            <a href="/fork">Fork?</a> | 
-            <a href="/concept">Concept</a> | 
-            <a href="/checklist">Checklist</a> |
-            <a href="/logo">Logo</a> | 
-            <a href="/translations">Translations</a>
+            <a href="/">The Map</a> | 
+            <a href="/concept">The Concept</a> | 
+            <a href="/fork#the-meme">The Meme</a>
         </center>
     </div>
 </div>