chore(i18n): refactor and cleanup (#805)

* checkpoint

* finish

* docs

quartz/util/lang.ts

@@ -1,11 +1,3 @@
-export function pluralize(count: number, s: string): string {
-  if (count === 1) {
-    return `1 ${s}`
-  } else {
-    return `${count} ${s}s`
-  }
-}
-
 export function capitalize(s: string): string {
   return s.substring(0, 1).toUpperCase() + s.substring(1)
 }