Move "Getting Started" menu to a more suitable place

[jjnesbitt]

Currently, the "Getting Started" dialog is a v-menu that wraps the whole template of WorkspaceDialog.vue. This causes a confusing situation, as we're not using the menu in that component really, and it causes redundancies with the template (see 7f64635). It'd be better to put this somewhere more concrete, like Sidebar.vue.

@jtomeck Did you have a particular reason for putting the v-menu in WorkspaceDialog.vue?

[jtomeck]

Inexperience is probably the best explanation I could give you. Since I wanted it positioned next to the new workspace button, I think putting it there auto positioned it for me. I'm open to better ways of doing it though.