message: Fix wrong case in readme status badges
diff: A superset of Roku's BrightScript language. Compiles to standard BrightScript.
  -[![build](https://img.shields.io/github/workflow/status/rokucommunity/BrighterScript/build.svg?logo=github)](https://github.com/rokucommunity/BrighterScript/actions?query=workflow%3Abuild)
  -[![Coverage Status](https://coveralls.io/repos/github/rokucommunity/BrighterScript/badge.svg?branch=master)](https://coveralls.io/github/rokucommunity/BrighterScript?branch=master)
  -[![NPM Version](https://badge.fury.io/js/BrighterScript.svg?style=flat)](https://npmjs.org/package/BrighterScript)
  +[![build](https://img.shields.io/github/workflow/status/rokucommunity/brighterscript/build.svg?logo=github)](https://github.com/rokucommunity/brighterscript/actions?query=workflow%3Abuild)
  +[![Coverage Status](https://coveralls.io/repos/github/rokucommunity/brighterscript/badge.svg?branch=master)](https://coveralls.io/github/rokucommunity/brighterscript?branch=master)
  +[![NPM Version](https://badge.fury.io/js/brighterscript.svg?style=flat)](https://npmjs.org/package/brighterscript)
  ## Overview
  