Update README.md

Added  usage guidelines for abhishekkrthakur#29

README.md

@@ -50,8 +50,9 @@ $ ColabCode()
 # - port: the port you want to run code-server on, default 10000
 # - password: password to protect your code server from being accessed by someone else. Note that there is no password by default!
 # - mount_drive: True or False to mount your Google Drive
+# - option: "localtunnel" or "ngrok" to use respective tunneling services
 
-$ ColabCode(port=10000, password="abhishek", mount_drive=True)
+$ ColabCode(port=10000, password="abhishek", mount_drive=True,option="localtunnel")
 ```
 ## How to use it?
 Colab starter notebook: [![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/abhishekkrthakur/colabcode/blob/master/colab_starter.ipynb)