Add functionality to the Modify button on My Demos page

## Description
The _Modify_ button on _My Demos_ page does not work.

## Expected Behavior
On clicking the _Modify_ button of a demo, the user should be redirected to the appropriate page where the the user can make changes to the content and specifications of that demo.

## Actual Behavior
On clicking the _Modify_ button of a demo, the user is not redirected to any page.

## Steps to Reproduce the Problem

1. Navigate to the My Demos page.
2. Click on the _Modify_ button.
3. Nothing happens on clicking the button.

Thanks!