- Added a Dockerfile to allow the editor to be served using docker containers

- Updated README with docker instructions

Dockerfile

@@ -0,0 +1,15 @@
+FROM nodesource/xenial:6.1.0
+
+EXPOSE 8888
+
+ENV HOME /maputnik
+RUN mkdir ${HOME}
+
+COPY . ${HOME}/
+
+WORKDIR ${HOME}
+
+RUN npm install -d --dev
+RUN npm run build
+
+CMD npm run start -- --host 0.0.0.0