Theme/Style Gatsby Frontend

[dtoki]

Restyle gatsby site to fit the last train.

~@tiakindele can you take this on and flesh out the issue a bit more?~

• [x] colour scheme
• [x] updates hosts
• [x] Add new favicon
• [x] update footer social links
• [x] hide the newletter
• [x] change polish to english on the frontend
• [x] update the fonts using brand guide
• [x] hide "downlod app section"

[dtoki]

@tiakindele break this down to smaller issues and assign some to me.