Update 'README.md'

README.md

@@ -1,3 +1,20 @@
-# oui
+## oui.py
+
+Little program to lookup the vendor string for MAC addresses.
+ 
+The first 3 octetts of a MAC address denote the manufacturer of the network card.
+I use this at work, when analyzing unknown or unwanted traffic, to know who the culprit may be. 
+
+Usage:
+
+    python3 oui.py MAC [--force] [--file /var/tmp/oui.txt]
+    --force - Forces the download of the file, ignoring the one week caching
+    --file - Overrides the storage location and also uses an existing file.
+    
+This project is in the public domain.
+
+<!--suppress HtmlDeprecatedAttribute -->
+<p align="center">
+<a href='https://ko-fi.com/L3L31HXRQ' target='_blank'><img height='36' style='border:0;height:36px;' src='https://cdn.ko-fi.com/cdn/kofi2.png?v=2' border='0' alt='Buy Me a Coffee at ko-fi.com' /></a>
+</p>
 
-MAC address vendor lookup via the official database