Publicly shareable URLs polish

[joemasilotti]

The goal of this issue is to clean up the UX around #646.

A PR addressing this issue should:

• When the “Share” button is clicked show a modal explaining how the public page works
• A Cancel buttons closes the modal
• A “Copy link” button copies the link to the clipboard

This issue is blocked by #646. This issue is no longer blocked.

Reminder to include a disclaimer that the developer's email address will be shared if they share their profile via this method.

[sarvaiyanidhi]

Hi @joemasilotti I would like to work further on this issue.. can you please assign it to me?

[joemasilotti]

Sure thing! All yours @sarvaiyanidhi. Thanks again for all the help. :)

[joemasilotti]

Closed via #718.