Change metadata to french

src/components/Metadata.vue

@@ -71,16 +71,16 @@ export default {
       pagination: {},
       headers: [
         {
-          text: 'Document Metadata',
+          text: 'Titre',
           align: 'left',
           sortable: false,
           value: 'title'
         },
         { text: 'Collection', value: 'collection' },
-        { text: 'Author', value: 'author' },
-        { text: 'Recipient', value: 'recipient' },
-        { text: 'Gender', value: 'gender' },
-        { text: 'Place', value: 'place' },
+        { text: 'Auteur(e)', value: 'author' },
+        { text: 'Destinataire', value: 'recipient' },
+        { text: 'Sexe', value: 'gender' },
+        { text: 'Lieu', value: 'place' },
         { text: 'Date', value: 'date' }
       ],
       items: null