add circle ci status badge code example

Example: add circle ci status badge template

# Template:
[![<ORG_NAME>](https://circleci.com/<VCS>/<ORG_NAME>/<PROJECT_NAME>.svg?style=svg)](<LINK>)

# Example:
[![CircleCI](https://circleci.com/gh/circleci/circleci-docs.svg?style=svg)](https://circleci.com/gh/circleci/circleci-docs)

# Example for specific branch:
[![CircleCI](https://circleci.com/gh/circleci/circleci-docs/tree/teesloane-patch-5.svg?style=svg)](https://circleci.com/gh/circleci/circleci-docs/?branch=teesloane-patch-5)