Updated README and fixed version to 0.3.7

Dockerfile

@@ -1,3 +1,3 @@
 FROM node:12.13-alpine3.10
 
-RUN npm install -g @lhci/cli@0.3.x
+RUN npm install -g @lhci/cli@0.3.7

README.md

@@ -1,4 +1,18 @@
 # lighthouse-ci-docker
 
+[![Docker Automated build](https://img.shields.io/docker/automated/jrottenberg/ffmpeg.svg)](https://hub.docker.com/r/pixboost/lighthouse-ci-cli/)
+
 Docker image for [Lighthouse CI CLI](https://github.com/GoogleChrome/lighthouse-ci)
 
+## Usage
+
+We are using this image in our Bitbucket Pipeline as a step to run LH tests and upload results.
+
+```
+docker pull pixboost/lighthouse-ci-cli
+```
+
+## Advantages
+
+* Using slim node image and trying to keep it as small as possible. Currently - 55MB
+* Using tags to pin a specific lhci version