docs: update readme

README.md

@@ -1,6 +1,6 @@
 # rn-section-grid-list
 
-SectionList with columns
+This package for React Native provides SectionGridList component which works the same as usual SectionList but also adds the ability to render columns in sections by providing numColumns parameter (as in FlatList).
 
 ## Installation
 
@@ -11,11 +11,55 @@ npm install rn-section-grid-list
 ## Usage
 
 ```js
-import { multiply } from 'rn-section-grid-list';
+import { SectionGridList } from 'rn-section-grid-list';
 
 // ...
 
-const result = await multiply(3, 7);
+const sections = useMemo(
+  () => [
+    { data: ['00', '11', '22'], key: 'Section #1' },
+    { data: ['33', '44', '55', '66', '77'], key: 'Section #2' },
+    { data: ['88'], key: 'Section #3' },
+  ],
+  []
+);
+
+// ...
+
+<SectionGridList
+  RowSeparatorComponent={<View style={styles.rowSeparator} />}
+  renderSectionHeader={({ section }) => (
+    <Text style={styles.sectionHeaderText}>{section.key}</Text>
+  )}
+  numColumns={3}
+  renderItem={({ item }) => (
+    <View style={styles.item}>
+      <Text>{item}</Text>
+    </View>
+  )}
+  sections={sections}
+/>;
+
+// ...
+
+const styles = StyleSheet.create({
+  item: {
+    alignItems: 'center',
+    backgroundColor: 'pink',
+    height: Dimensions.get('window').width * 0.3,
+    justifyContent: 'center',
+    minWidth: '30%',
+  },
+  rowSeparator: {
+    height: Dimensions.get('window').width * 0.05,
+  },
+  sectionHeaderText: {
+    fontSize: 16,
+    fontWeight: 'bold',
+    marginVertical: 8,
+    textAlign: 'center',
+  },
+});
 ```
 
 ## Contributing