Is your feature request related to a problem? Please describe...

Before the javascript has loaded, clicking on the b-nav-item-dropdown causes the page to change and there's no way to control what page the b-nav-item-dropdown goes to because it's hardcoded to '#'.

Describe the solution you'd like

Have b-nav-item-dropdown support a new href property that would allow changing the href while keeping the default as '#'.

The href value of '#' is hardcoded here: