Add docker-compose file

Just to make it easier to do development without installing all the jekyll stuff yourself.

All you need is docker+docker-compose and run 'docker-compose up' in the root of the project.

docker-compose.yml

@@ -0,0 +1,9 @@
+
+jekyll:
+    image: jekyll/jekyll
+    command: jekyll serve --livereload --reload_port 35729
+    ports:
+        - 4000:4000
+        - 35729:35729
+    volumes:
+        - .:/srv/jekyll