Add stricter ESLint rules for Typescript files (#24926)

app/javascript/mastodon/components/relative_timestamp.tsx

@@ -1,5 +1,7 @@
 import React from 'react';
-import { injectIntl, defineMessages, InjectedIntl } from 'react-intl';
+
+import type { InjectedIntl } from 'react-intl';
+import { injectIntl, defineMessages } from 'react-intl';
 
 const messages = defineMessages({
   today: { id: 'relative_time.today', defaultMessage: 'today' },
@@ -187,16 +189,16 @@ const timeRemainingString = (
   return relativeTime;
 };
 
-type Props = {
+interface Props {
   intl: InjectedIntl;
   timestamp: string;
   year: number;
   futureDate?: boolean;
   short?: boolean;
-};
-type States = {
+}
+interface States {
   now: number;
-};
+}
 class RelativeTimestamp extends React.Component<Props, States> {
   state = {
     now: this.props.intl.now(),