Control-click is mishandled

[QuLogic]

On the user guide, middle-clicking on any link will open it in a new tab. However, Control-clicking will just open the link in the current tab, if it's internal. If it's an external link, then it will behave correctly and open in a new tab.

For example, on the installation page, control-clicking on the "make your first Dash app" will open in the current tab, but control-clicking any of the "changelog" links will open in a background tab.

Using Firefox 72.0.1 on Linux.

[alexcjohnson]

On Mac the equivalent is Cmd-click, and shows the same problem. Moved this issue to the dcc repo, as the fix should be in dcc.Link. Thanks for the report @QuLogic!