Update README docker section

Author: shesek

README.md

@@ -28,16 +28,18 @@ $ nanopos --items-path items.yaml --charge-token mySecretToken --currency USD
 HTTP server running on localhost:9116
 ```
 
-## Running from Docker
+## Running with Docker
 
-Nanopos includes a Dockerfile and .dockerignore to allow for fast setup and running from a docker container based on node:carbon. To run from the container with port 9112 and port 9116 exposed, first build the image with:
+Nanopos 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/nanopos .
 ```
-docker build -t elements_project/nanopos .
-```
-and then run with
-```
-docker run -p9116:9116 -d elements_project/nanopos
+
+and then run with:
+
+```bash
+$ docker run -p9116:9116 -e CHARGE_URL=http://[charge-url]/ -e CHARGE_TOKEN=[access-token] elements_project/nanopos
 ```
 
 That's it! The web server should now be running on port 9116 and ready to accept payments.