Add children type to fix ts error (#1073)

Author: aarondunphy

docs/react-testing-library/setup.mdx

@@ -84,7 +84,7 @@ import {ThemeProvider} from 'my-ui-lib'
 import {TranslationProvider} from 'my-i18n-lib'
 import defaultStrings from 'i18n/en-x-default'
 
-const AllTheProviders: FC = ({children}) => {
+const AllTheProviders: FC<{children: React.ReactNode}> = ({children}) => {
   return (
     <ThemeProvider theme="light">
       <TranslationProvider messages={defaultStrings}>