Hi Gaurav - You may have already had this answered, but here it is again. Hacker League uses the Markdown to create wiki pages. You may find this link helpful to learn more about it -
Please let us know if you have any further questions.
Amit @ Team Hacker League
Yes, you can always update your entry after the deadline by going to the application and clicking the "update" button. The person who submitted the app is responsible for maintaining accurate team and app information.