Update README.md with examples for custom search with filters

Author: reginaalyssa

README.md

@@ -152,6 +152,50 @@ JSON output:
 }
 ```
 
+#### Custom Search With Filters <!-- omit in toc -->
+
+If you want to enable filtering, you must add your attributes to the `filterableAttributes` index setting.
+
+```ruby
+index.update_filterable_attributes([
+  'id',
+  'genres'
+])
+```
+
+You only need to perform this operation once.
+
+Note that MeiliSearch will rebuild your index whenever you update `filterableAttributes`. Depending on the size of your dataset, this might take time. You can track the process using the [update status](https://docs.meilisearch.com/reference/api/updates.html#get-an-update-status).
+
+Then, you can perform the search:
+
+```ruby
+index.search('road', { filter: ['id > 2 AND genres = Adventure'] })
+```
+
+JSON output:
+
+```json
+{
+  "hits": [
+    {
+      "id": 4,
+      "title": "Mad Max: Fury Road",
+      "genres": [
+        "Adventure",
+        "Science Fiction"
+      ]
+    }
+  ],
+  "nbHits": 1,
+  "exhaustiveNbHits": false,
+  "query": "road",
+  "limit": 20,
+  "offset": 0,
+  "processingTimeMs": 0
+}
+```
+
 ## 🤖 Compatibility with MeiliSearch
 
 This package only guarantees the compatibility with the [version v0.23.0 of MeiliSearch](https://github.com/meilisearch/MeiliSearch/releases/tag/v0.23.0).