docs: add events to README

Signed-off-by: Snehil Shah <snehilshah.989@gmail.com>

Author: Snehil-Shah

lib/node_modules/@stdlib/plot/table/unicode/README.md

@@ -506,6 +506,36 @@ var str = table.render();
 
 * * *
 
+### Events
+
+#### 'change'
+
+Emitted whenever a property value changes.
+
+```javascript
+var table = new UnicodeTable();
+
+table.on( 'change', onChange );
+
+function onChange() {
+    console.log( 'A property was updated.' );
+}
+```
+
+#### 'render'
+
+Emitted whenever a sparkline is rendered.
+
+```javascript
+var table = new UnicodeTable();
+
+table.on( 'render', onRender );
+
+function onRender( str ) {
+    console.log( 'Rendered table: %s', str );
+}
+```
+
 </section>
 
 <!-- /.usage -->