docs: add info to activitytimeline examples

src/components/ActivityTimeline/readme.md

@@ -1,4 +1,5 @@
-##### ActivityTimeline base example:
+# The basic ActivityTimeline
+##### This example shows a simple activity timeline that vertically displays a list of events in chronological order.
 
 ```js
 import React from 'react';
@@ -39,7 +40,7 @@ const container = { width: 500, margin: 'auto', marginTop: 36, };
 ```
 
 # ActivityTimeline as accordion
-##### ActivityTimeline can be used as accordion. You can do so by using the `variant` prop.
+##### ActivityTimeline can be used as accordion. You can do so by implementing the `variant` prop.
 
 ```js
 import React, { useState, useMemo, useCallback, useEffect } from 'react';