docs: Improve ignores documentation (#17239)

* docs: Improve `ignores` documentation

* Another note about `dir/` vs. `dir/**` in non-global patterns

* Update docs/src/use/configure/configuration-files-new.md

Clarifiy a sentence

Co-authored-by: Milos Djermanovic <milos.djermanovic@gmail.com>

---------

Co-authored-by: Milos Djermanovic <milos.djermanovic@gmail.com>

docs/src/use/configure/configuration-files-new.md

@@ -116,7 +116,9 @@ export default [
 
 Here, the configuration object excludes files ending with `.config.js` except for `eslint.config.js`. That file still has `semi` applied.
 
-If `ignores` is used without `files` and any other setting, then the configuration object applies to all files except the ones specified in `ignores`, for example:
+Non-global `ignores` patterns can only match file names. A pattern like `"dir-to-exclude/"` will not ignore anything. To ignore everything in a particular directory, a pattern like `"dir-to-exclude/**"` should be used instead.
+
+If `ignores` is used without `files` and there are other keys (such as `rules`), then the configuration object applies to all files except the ones specified in `ignores`, for example:
 
 ```js
 export default [
@@ -145,6 +147,9 @@ export default [
 
 This configuration specifies that all of the files in the `.config` directory should be ignored. This pattern is added after the default patterns, which are `["**/node_modules/**", ".git/**"]`.
 
+Note that only global `ignores` patterns can match directories.
+`ignores` patterns that are specific to a configuration will only match file names.
+
 #### Cascading configuration objects
 
 When more than one configuration object matches a given filename, the configuration objects are merged with later objects overriding previous objects when there is a conflict. For example: