Add placeholder dashboard

I'm not entirely sure what I'd like to show just yet here. It would be nice to put a little bit of information in here, even at this stage.

Here's what I'm thinking, generally:

- Upcoming interviews 
- Upcoming application deadlines
- Action items: follow ups that need to be sent, applications that need to be sent

- Total stats (ie, you have applied to x jobs and have x interviews or whatever)
- Progress this week (number of jobs applied to, number of interviews) 

Encouraging words would be nice as well. Maybe it could actually rotate through a series: "You get 'em, tiger!" "Remember, it only takes a single offer!" etc. 

Closes #59.