Update gitignore (sorry)

electron/node_modules/simple-update-notifier/src/isNpmOrYarn.ts

@@ -0,0 +1,12 @@
+import process from 'process';
+
+const packageJson = process.env.npm_package_json;
+const userAgent = process.env.npm_config_user_agent;
+const isNpm6 = Boolean(userAgent && userAgent.startsWith('npm'));
+const isNpm7 = Boolean(packageJson && packageJson.endsWith('package.json'));
+
+const isNpm = isNpm6 || isNpm7;
+const isYarn = Boolean(userAgent && userAgent.startsWith('yarn'));
+const isNpmOrYarn = isNpm || isYarn;
+
+export default isNpmOrYarn;