Add usage section

Author: AB-xdev

README.md

@@ -10,6 +10,26 @@ A Vaadin Flow component for filtering Grids.
 
 ![demo](assets/demo.png)
 
+# Usage
+
+Here is a very simple example how the GridFilter can be used:
+```java
+Grid<Person> grid = createGrid();
+
+GridFilter<Person> filter = GridFilter.createDefault(grid)
+  .withFilterableField("ID", Person::id, Integer.class)
+  .withFilterableField("First Name", Person::firstName, String.class);
+
+this.add(filter, grid);
+```
+
+To get started further it's recommended to have a look at the [demo](./vaadin-grid-filter-demo).<br/>
+A description how to get it running can be found [below](#run-the-demo).
+
+> [!NOTE]
+> This component is designed for "in memory" filtering of small to medium sized amounts of data.<br/>
+> Filtering multiple thousand items with multiple complex filtering coditions can drastically impact performance and make the UI unresponsive!<br/> In these cases it's recommended to use backend filtering solutions like Database Queries or [ElasticSearch](https://en.wikipedia.org/wiki/Elasticsearch) in combination with a customized UI search framework.<br/>
+> If you need help in implementing these feel free to [contact us](#support).
 
 ## Installation
 [Installation guide for the latest release](https://github.com/xdev-software/vaadin-grid-filter/releases/latest#Installation)