chore(CI): update master branch references

Author: MichaelDeBoey

.github/workflows/ci.yml

@@ -1,9 +1,9 @@
 name: CI
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
-    branches: [master]
+    branches: [main]
   schedule:
     - cron: 0 0 * * 0
 

README.md

@@ -3,7 +3,7 @@
 [![npm version](https://img.shields.io/npm/v/regexpp.svg)](https://www.npmjs.com/package/regexpp)
 [![Downloads/month](https://img.shields.io/npm/dm/regexpp.svg)](http://www.npmtrends.com/regexpp)
 [![Build Status](https://github.com/mysticatea/regexpp/workflows/CI/badge.svg)](https://github.com/mysticatea/regexpp/actions)
-[![codecov](https://codecov.io/gh/mysticatea/regexpp/branch/master/graph/badge.svg)](https://codecov.io/gh/mysticatea/regexpp)
+[![codecov](https://codecov.io/gh/mysticatea/regexpp/branch/main/graph/badge.svg)](https://codecov.io/gh/mysticatea/regexpp)
 [![Dependency Status](https://david-dm.org/mysticatea/regexpp.svg)](https://david-dm.org/mysticatea/regexpp)
 
 A regular expression parser for ECMAScript.