Update README.md

README.md

@@ -4,7 +4,7 @@ The waybackpy is python wrapper for [Internet Archive](https://en.wikipedia.org/
 
 ## Usage
 
-### Capturing/Saving a url/website. Using save() function.
+### Capturing/Saving a url/website. Using save().
 
 waybackpy.save(url, UA=user_agent)
 
@@ -19,3 +19,19 @@ This should print something similar to the following archived url:
 ```
 https://web.archive.org/web/20200504141153/https://github.com/akamhy/waybackpy
 ```
+
+### Retiving the oldest archive for a url. Using oldest().
+
+waybackpy.oldest(url, UA=user_agent)
+
+```python
+import waybackpy
+# retriving the oldest archive on wayback machine.
+# Default user-agent (UA) is "waybackpy python package", if not specified in the call.
+oldest_archive = waybackpy.oldest("https://www.google.com/", UA = "Any-User-Agent")
+print(oldest_archive)
+```
+This returns the oldest available archive for google.com (Check it out! It's really fascinating! and follow those blue links.)
+```
+http://web.archive.org/web/19981111184551/http://google.com:80/
+```