Update Readme

**Tagged GSSOC site is not working**
Linked site is not working and Image is not showing properly in README.md
**To Reproduce**
Steps to reproduce the behavior:
1. Go to 'AmbSQL github page'
2. Click on 'README.md'
3. Scroll down to 'https://github.com/ambujraj/AmbSQL/blob/master/README.md#important-notice'
4. See error

**Expected behavior**
GSSOC site should be opened when we click on it.