chore: Move to Typescript (#2783)

This PR moves the entire project to Typescript. Due to the ~1000 ignores this will lead to a messy codebase for a while, but the churn is worth it – all of those ignore comments are places that were never type-safe previously.

closes #1282

app/styles/animations.ts

@@ -1,4 +1,3 @@
-// @flow
 import { keyframes } from "styled-components";
 
 export const fadeIn = keyframes`

app/styles/globals.ts

@@ -1,4 +1,3 @@
-// @flow
 import { createGlobalStyle } from "styled-components";
 import styledNormalize from "styled-normalize";