Updating the UI of Giraffe app

[scandindian]

Solving issue https://github.com/fossasia/giraffe/issues/2

Here are some samples for changes

I wrote a blog about this as it is a major change in the app https://docs.google.com/document/d/1uxRO64ZgqU2haZWCHJFexSPvL4mD3KkNHqGoGN7nHOY/edit?usp=sharing

Please review @the-dagger @mariobehling