Small a11y fixes

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/components/NavBar.vue

@@ -1,5 +1,8 @@
 <template>
-  <nav class="bg-white border-gray-200 px-2 sm:px-4 py-2.5 dark:bg-zinc-900">
+  <nav
+    class="bg-white border-gray-200 px-2 sm:px-4 py-2.5 dark:bg-zinc-900"
+    id="navbar"
+  >
     <div class="container mx-auto flex flex-wrap items-center mx-auto gap-4">
       <router-link :to="{ name: RouteName.HOME }" class="flex items-center">
         <MobilizonLogo class="w-40" />

js/src/components/PageFooter.vue

@@ -21,6 +21,7 @@
     >
       <li>
         <o-select
+          class="text-black dark:text-white"
           :aria-label="t('Language')"
           v-model="locale"
           :placeholder="t('Select a language')"