Add Windows to GitHub Actions CI matrix

Summary: Pull Request resolved: https://github.com/facebook/flipper/pull/741

Reviewed By: jknoxville

Differential Revision: D19371114

fbshipit-source-id: 07c6bd71e58011cc3fffa34354546eb773e3fc3d

.eslintrc.js

@@ -10,7 +10,7 @@
 const fbjs = require('eslint-config-fbjs');
 
 // enforces copyright header and @format directive to be present in every file
-const pattern = /^\*\n[\S\s]*Facebook[\S\s]* \* @format\n/;
+const pattern = /^\*\r?\n[\S\s]*Facebook[\S\s]* \* @format\r?\n/;
 
 const prettierConfig = {
   requirePragma: true,