feat: display the reading time in a formatted for the locale

The display of the reading time for each page is currently based
on the assumption that the page is in English. This change makes
the Intl API is used to display the reading time in a format
appropriate for the locale of the translated language.

Author: okuryu

apps/site/components/withMetaBar.tsx

@@ -20,6 +20,10 @@ const WithMetaBar: FC = () => {
   const lastUpdated = frontmatter.date
     ? formatter.dateTime(new Date(frontmatter.date), DEFAULT_DATE_FORMAT)
     : undefined;
+  const readingTimeText = formatter.number(Math.round(readingTime.minutes), {
+    style: 'unit',
+    unit: 'minute',
+  });
 
   const usernames =
     frontmatter.authors?.split(',').map(author => author.trim()) ?? [];
@@ -39,7 +43,7 @@ const WithMetaBar: FC = () => {
     <MetaBar
       items={{
         'components.metabar.lastUpdated': lastUpdated,
-        'components.metabar.readingTime': readingTime.text,
+        'components.metabar.readingTime': readingTimeText,
         ...(usernames.length && {
           [`components.metabar.${usernames.length > 1 ? 'authors' : 'author'}`]:
             (