Add (closable) warning on everypage

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

js/src/App.vue

@@ -1,6 +1,18 @@
 <template>
   <div id="mobilizon">
     <NavBar />
+    <div class="container">
+      <b-message type="is-danger" :title="$t('Warning').toLocaleUpperCase()" closable>
+        <p>{{ $t('This is a demonstration site to test the beta version of Mobilizon.') }}</p>
+        <p v-html="$t('<b>Please do not use it in any real way</b>: everything you create here (accounts, events, identities, etc.) will be automatically deleted every 48 hours.')" />
+        <p>
+          <span v-html="$t('Mobilizon is under development, we will add new features to this site during regular updates, until the release of <b>version 1 of the software in the first half of 2020</b>.')" />
+          <i18n path="In the meantime, please consider that the software is not (yet) finished. More information {onBlog}.">
+            <a href='https://framablog.org/?p=18299'>{{ $t('on our blog') }}</a>
+          </i18n>
+        </p>
+      </b-message>
+    </div>
     <main>
       <transition name="fade" mode="out-in">
         <router-view />