Update README.md badges

Author: Tomdango

README.md

@@ -2,7 +2,7 @@
 
 NHS.UK Frontend ported to React
 
-[![GitHub Actions CI Status](https://github.com/NHSDigital/nhsuk-react-components/workflows/CI/badge.svg)](https://github.com/NHSDigital/nhsuk-react-components/actions?query=workflow%3A%22CI+Build%22+branch%3Amaster) [![JavaScript Style Guide](https://img.shields.io/badge/code_style-airbnb-brightgreen.svg)](https://github.com/airbnb/javascript) [![Bundle Size](https://img.shields.io/bundlephobia/minzip/nhsuk-react-components.svg)](https://bundlephobia.com/result?p=nhsuk-react-components@1.0.0-rc.1)
+[![GitHub Actions CI Status](https://github.com/NHSDigital/nhsuk-react-components/workflows/CI/badge.svg)](https://github.com/NHSDigital/nhsuk-react-components/actions?query=workflow%3A%22CI+Build%22+branch%3Amain) [![JavaScript Style Guide](https://img.shields.io/badge/code_style-airbnb-brightgreen.svg)](https://github.com/airbnb/javascript) [![Bundle Size](https://img.shields.io/bundlephobia/minzip/nhsuk-react-components.svg)](https://bundlephobia.com/result?p=nhsuk-react-components)
 
 ## Coming from 0.x?