Added G20 sub category page

Signed-off-by: Jim Martens <github@2martens.de>

_data/header-menu.yml

@@ -1,6 +1,9 @@
 items:
   - link: /politics/
     title: Politics
+    items:
+      - link: /politics/g20/
+        title: G20
   - link: /about/
     title: About
   - link: /media/

politics/g20/index.html

@@ -0,0 +1,17 @@
+---
+layout: category
+title: G20
+category: G20
+sidebarboxes: author politics_qanda
+parent_link: /politics/
+---
+
+<h1>G20</h1>
+
+<p>
+    On this page you can find all my blog posts related to the G20 summit 2017 in Hamburg. At this point this includes
+    only the reports from the G20 special committee that was installed after the fact by the Hamburg parliament to
+    investigate everything related to G20 and the violence that erupted in that time frame.
+</p>
+
+<h2>Blog posts</h2>

politics/index.html

@@ -11,7 +11,7 @@ sidebarboxes: author politics_qanda
     On this page you can find all my political activities. If you have questions or suggestions, feel free to contact
     me via the email address provided in the sidebar box. Below you can find blog posts related to politics. When it
     makes sense I will add pages detailing specific topics. Such may be the case for election campaigns and the positions
-    I represent in them.
+    I represent in them. Already available is the sub category G20 which makes all posts related to G20 easier to access.
 </p>
 
 <h2>Blog posts</h2>