[BUG]: Re-positioning of the GitHub icon with the rest icons.

**Issue description**
The GitHub icon is placed separately at the bottom right of the website; whereas the rest of the social icons are on the left.
Therefore, it would be more professional if it was placed with the rest of them.

**Steps to reproduce the issue**
1. Go to 'grpc.io'
2. Click on 'scroll'
3. Scroll down to bottom/end.
4. GitHub icon is placed at right.

**Expected behavior**
It would be more professional if the GitHub icon was placed with the rest of them on the left part of the screen.

**Screenshots**