docker-compose file

Changes to be committed:
  new file:   docs/docker-compose.yml

docs/docker-compose.yml

@@ -0,0 +1,13 @@
+# run jekyll with docker container
+#
+# install docker && docker-compose
+# https://docs.docker.com/compose/install/
+# then run docker-compose up
+
+jekyll:
+    image: jekyll/jekyll:pages
+    command: jekyll serve --watch --incremental
+    ports:
+        - 4000:4000
+    volumes:
+        - .:/srv/jekyll