docs: update transpileDependencies documentation

docs/config/README.md

@@ -183,10 +183,12 @@ Deprecated since Vue CLI 3.3, please use [`publicPath`](#publicPath) instead.
 
 ### transpileDependencies
 
-- Type: `Array<string | RegExp>`
-- Default: `[]`
+- Type: `boolean | Array<string | RegExp>`
+- Default: `false`
+
+  By default `babel-loader` ignores all files inside `node_modules`. You can enable this option to avoid unexpected untranspiled code from third-party dependencies.
 
-  By default `babel-loader` ignores all files inside `node_modules`. If you want to explicitly transpile a dependency with Babel, you can list it in this option.
+  Transpiling all the dependencies could slow down the build process, though. If build performance is a concern, you can explicitly transpile only some of the dependencies by passing an array of package names or name patterns to this option.
 
 ::: warning Jest config
 This option is not respected by the [cli-unit-jest plugin](#jest), because in jest, we don't have to transpile code from `/node_modules` unless it uses non-standard features - Node >8.11 supports the latest ECMAScript features already.

docs/core-plugins/babel.md

@@ -6,10 +6,12 @@
 
 Uses Babel 7 + `babel-loader` + [@vue/babel-preset-app](https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/babel-preset-app) by default, but can be configured via `babel.config.js` to use any other Babel presets or plugins.
 
-By default, `babel-loader` excludes files inside `node_modules` dependencies. If you wish to explicitly transpile a dependency module, you will need to add it to the `transpileDependencies` option in `vue.config.js`:
+By default, `babel-loader` excludes files inside `node_modules` dependencies. You can enable the `transpileDependencies` option in `vue.config.js` to transpile the dependencies. Or, if you want to only transpile some of the dependency modules, you can pass an array to the `transpileDependencies` option:
 
 ``` js
 module.exports = {
+  // Set to `true` to transpile all dependencies.
+  // Or pass an array to transpile selectively.
   transpileDependencies: [
     // can be string or regex
     'my-dep',

docs/zh/config/README.md

@@ -183,10 +183,13 @@ module.exports = {
 
 ### transpileDependencies
 
-- Type: `Array<string | RegExp>`
-- Default: `[]`
+- Type: `boolean | Array<string | RegExp>`
+- Default: `false`
+
+  默认情况下 `babel-loader` 会忽略所有 `node_modules` 中的文件。你可以启用本选项，以避免构建后的代码中出现未转译的第三方依赖。
+
+  不过，对所有的依赖都进行转译可能会降低构建速度。如果对构建性能有所顾虑，你可以只转译部分特定的依赖：给本选项传一个数组，列出需要转译的第三方包包名或正则表达式即可。
 
-  默认情况下 `babel-loader` 会忽略所有 `node_modules` 中的文件。如果你想要通过 Babel 显式转译一个依赖，可以在这个选项中列出来。
 
 ### productionSourceMap