[@type/react-infinite-calendar] Describe locale.locale in detail (#42703)

* update: locale.locale

* update: test case

* Update locale types in more detail

types/react-infinite-calendar/index.d.ts

@@ -47,6 +47,10 @@ export interface ReactInfiniteCalendarProps {
         todayHelperRowOffset?: number;
     };
     locale?: {
+        locale?: {
+            distanceInWords: (token: any, count: any, options: any) => any,
+            format: () => any;
+        },
         blank?: string;
         headerFormat?: string;
         todayLabel?: {

types/react-infinite-calendar/react-infinite-calendar-tests.tsx

@@ -32,6 +32,10 @@ const test: React.SFC = () => (
           todayHelperRowOffset: 4,
         }}
         locale={{
+          locale: {
+            distanceInWords: () => {},
+            format: () => {}
+          },
           blank: 'Select a date...',
           headerFormat: 'ddd, MMM Do',
           todayLabel: {