docs: use a less ambiguous date format for 'Last updated' (#944)

Author: skirtles-code

src/.vuepress/config.js

@@ -461,6 +461,21 @@ module.exports = {
     }
   },
   plugins: [
+    [
+      '@vuepress/last-updated',
+      {
+        transformer(timestamp) {
+          const date = new Date(timestamp)
+
+          const digits = [
+            date.getUTCFullYear(), date.getUTCMonth() + 1, date.getUTCDate(),
+            date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds()
+          ].map(num => String(num).padStart(2, '0'))
+
+          return '{0}-{1}-{2}, {3}:{4}:{5} UTC'.replace(/{(\d)}/g, (_, num) => digits[num])
+        }
+      }
+    ],
     [
       '@vuepress/pwa',
       {