add languages

app/javascript/submission_form/completed.vue

@@ -222,7 +222,7 @@ export default {
             this.downloadUrls(urls)
           }
         } else {
-          alert('Failed to download files')
+          alert(this.t('failed_to_download_files'))
         }
       })
     },

app/javascript/submission_form/form.vue

@@ -1207,7 +1207,7 @@ export default {
         })
       }).catch(error => {
         if (error?.message === 'Image too small') {
-          alert('Signature is too small - please redraw.')
+          alert(this.t('signature_is_too_small_please_redraw'))
         } else {
           console.log(error)
         }