Add a design system (#34)

* Add theming system

* Add standard Button control and update RadioButtons

* Unify radiobutton with design system

* Update debug screen to have multiple views

* Add ToggleButton

* Update error controls to use design system

* Add typography to <Text> element

* Move DropdownButton into the design system

* Clean out old code

* Move Text into design system

* Add 'inverted' color palette

* Move LoadingPlaceholder into the design system

src/view/routes.ts

@@ -15,6 +15,7 @@ import {ProfileFollowers} from './screens/ProfileFollowers'
 import {ProfileFollows} from './screens/ProfileFollows'
 import {ProfileMembers} from './screens/ProfileMembers'
 import {Settings} from './screens/Settings'
+import {Debug} from './screens/Debug'
 
 export type ScreenParams = {
   navIdx: [number, number]
@@ -71,6 +72,7 @@ export const routes: Route[] = [
     'retweet',
     r('/profile/(?<name>[^/]+)/post/(?<rkey>[^/]+)/reposted-by'),
   ],
+  [Debug, 'Debug', 'house', r('/debug')],
 ]
 
 export function match(url: string): MatchResult {