docs: fix Ignoring Files section in config migration guide (#17392)

* docs: fix Ignoring Files section in config migration guide

* remove extra blank line

docs/src/use/configure/migration-guide.md

@@ -345,14 +345,14 @@ export default [
 
 With eslintrc, you can make ESLint ignore files by creating a separate `.eslintignore` file in the root of your project. The `.eslintignore` file uses the same glob pattern syntax as `.gitignore` files. Alternatively, you can use an `ignorePatterns` property in your eslintrc file.
 
-To ignore files with flat config, you can use the `ignores` property in a config object. The `ignores` property accepts an array of glob patterns. Note that flat config glob patterns do _not_ match dot files (e.g. `*.js` won't match `.dotfile.js`). Flat config does not support loading ignore patterns from `.eslintignore` files, so you'll need to migrate those patterns directly into flat config.
+To ignore files with flat config, you can use the `ignores` property in a config object. The `ignores` property accepts an array of glob patterns. Flat config does not support loading ignore patterns from `.eslintignore` files, so you'll need to migrate those patterns directly into flat config.
 
 For example, here's a `.eslintignore` example you can use with an eslintrc config:
 
 ```shell
 # .eslintignore
 temp.js
-.config/*
+config/*
 # ...other ignored files
 ```
 
@@ -362,21 +362,23 @@ temp.js
 // .eslintrc.js
 module.exports = {
     // ...other config
-    ignorePatterns: ["temp.js", ".config/*"],
+    ignorePatterns: ["temp.js", "config/*"],
 };
 ```
 
 Here are the same files ignore patterns in flat config:
 
 ```javascript
 export default [
+    // ...other config
     {
-        // ...other config
-        ignores: ["temp.js", ".config/*"]
+        ignores: ["**/temp.js", "config/*"]
     }
 ];
 ```
 
+Also, with flat config, dotfiles (e.g. `.dotfile.js`) are no longer ignored by default. If you want to ignore dotfiles, add files ignore pattern `"**/.*"`.
+
 ### Linter Options
 
 ESlintrc files let you configure the linter itself with the `noInlineConfig` and `reportUnusedDisableDirectives` properties.