add dockerfile and dockerignore

.dockerignore

@@ -0,0 +1,2 @@
+node_modules
+npm-debug.log

Dockerfile

@@ -0,0 +1,7 @@
+FROM node:carbon
+WORKDIR /opt/nanotip
+COPY . .
+RUN npm install
+ENV HOST=0.0.0.0
+EXPOSE 9115
+CMD node ./nanotip

README.md

@@ -58,6 +58,23 @@ $ nanotipd --help
     $ nanotipd -c http://localhost:9112 -t chargeSecretToken
 ```
 
+
+## Running with Docker
+
+Nantotip includes a Dockerfile to allow for fast setup using a docker container based on node:carbon. To run from the container with port 9116 exposed, first setup [Lightning Charge](https://github.com/ElementsProject/lightning-charge), then build the image with:
+
+```bash
+$ docker build -t elements_project/nanotip .
+```
+
+and then run with:
+
+```bash
+$ docker run -p 9115:9115 -e CHARGE_URL=http://[charge-url]/ -e CHARGE_TOKEN=[access-token] elements_project/nanotip
+```
+
+That's it! The web server should now be running on port 9115 and ready to accept payments.
+
 ## License
 
 MIT