refactor(cli-plugin-eslint): merge lint-staged config (#3487)

Author: Fengyuan Chen

packages/@vue/cli-plugin-eslint/__tests__/eslintGenerator.spec.js

@@ -129,8 +129,7 @@ test('lint on commit', async () => {
   expect(pkg.gitHooks['pre-commit']).toBe('lint-staged')
   expect(pkg.devDependencies).toHaveProperty('lint-staged')
   expect(pkg['lint-staged']).toEqual({
-    '*.js': ['vue-cli-service lint', 'git add'],
-    '*.vue': ['vue-cli-service lint', 'git add']
+    '*.{js,vue}': ['vue-cli-service lint', 'git add']
   })
   expect(pkg.vue).toEqual({
     lintOnSave: false

packages/@vue/cli-plugin-eslint/generator/index.js

@@ -77,8 +77,7 @@ module.exports = (api, { config, lintOn = [] }, _, invoking) => {
       'pre-commit': 'lint-staged'
     }
     pkg['lint-staged'] = {
-      '*.js': ['vue-cli-service lint', 'git add'],
-      '*.vue': ['vue-cli-service lint', 'git add']
+      '*.{js,vue}': ['vue-cli-service lint', 'git add']
     }
   }