Fixes clipped final row of pokemon entries

[beejaymay]

Hard coding calc to account for height of toolbar for now. This is sloppy, and should be made dynamic in the future.

Fixes #33

[ShadOoW]

In HomePage.css

.container {
  height: 100%;
  display: flex;
  flex-direction: column;
}

This should be more maintainable, cheers.

[beejaymay]

Quite right. Thank you.

Note to self: Stop forgetting about flex-box when working on Electron apps. It just works.