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/components/Sidebar/components/Disclosure.ts

@@ -0,0 +1,12 @@
+import { CollapsedIcon } from "outline-icons";
+import styled from "styled-components";
+
+const Disclosure = styled(CollapsedIcon)`
+  transition: transform 100ms ease, fill 50ms !important;
+  position: absolute;
+  left: -24px;
+
+  ${({ expanded }) => !expanded && "transform: rotate(-90deg);"};
+`;
+
+export default Disclosure;