Add French translation (#196)

* Added french version and title/description from json messages

* Revert back default language to en-US

* Code reviewed with prettier :)

* Updated json to add information field

* Updated json to add information block (missed on previous)

* Reviewed code language

* correction traduction "groupes étoilés" en "groupes favoris"

---------

Co-authored-by: Andy Trouvé <andy@strekol.eu>

src/app/page.tsx

@@ -1,31 +1,35 @@
 import { Button } from '@/components/ui/button'
 import { Github } from 'lucide-react'
+import { useTranslations } from 'next-intl'
 import Link from 'next/link'
 
 // FIX for https://github.com/vercel/next.js/issues/58615
 // export const dynamic = 'force-dynamic'
 
 export default function HomePage() {
+  const t = useTranslations()
   return (
     <main>
       <section className="py-16 md:py-24 lg:py-32">
         <div className="container flex max-w-screen-md flex-col items-center gap-4 text-center">
-          <h1 className="!leading-none font-bold text-3xl sm:text-5xl md:text-6xl lg:text-7xl landing-header py-2">
-            Share <strong>Expenses</strong> <br /> with <strong>Friends</strong>{' '}
-            & <strong>Family</strong>
+          <h1 className="!leading-none font-bold text-2xl sm:text-3xl md:text-4xl lg:text-5xl landing-header py-2">
+            {t.rich('Homepage.title', {
+              strong: (chunks) => <strong>{chunks}</strong>,
+            })}
           </h1>
           <p className="max-w-[42rem] leading-normal text-muted-foreground sm:text-xl sm:leading-8">
-            Welcome to your new <strong>Spliit</strong> instance! <br />
-            Customize this page by editing <em>src/app/page.tsx</em>.
+            {t.rich('Homepage.description', {
+              strong: (chunks) => <strong>{chunks}</strong>,
+            })}
           </p>
           <div className="flex gap-2">
             <Button asChild>
-              <Link href="/groups">Go to groups</Link>
+              <Link href="/groups">{t('Homepage.button.groups')}</Link>
             </Button>
             <Button asChild variant="secondary">
               <Link href="https://github.com/spliit-app/spliit">
                 <Github className="w-4 h-4 mr-2" />
-                GitHub
+                {t('Homepage.button.github')}
               </Link>
             </Button>
           </div>

src/i18n.ts

@@ -1,7 +1,7 @@
 import { getRequestConfig } from 'next-intl/server'
 import { getUserLocale } from './lib/locale'
 
-export const locales = ['en-US', 'fi'] as const
+export const locales = ['en-US', 'fi', 'fr-FR'] as const
 export type Locale = (typeof locales)[number]
 export type Locales = ReadonlyArray<Locale>
 export const defaultLocale: Locale = 'en-US'