add css container class for members vues

pages/membres/_hash.vue

 <template>
-  <main class="content container">
+  <main class="container">
     <NavigationLoader :isLoading="$apollo.queries.idFromHash.loading" />
     <transition name="fade">
       <div class="alert alert-danger" v-if="error">{{ error }}</div>

pages/membres/index.vue

 <template>
-<main class="content">
+<main class="container">
   <h2 class="text-center mb-5 font-weight-light">Membres</h2>
   <div class="row mb-4">
     <div class="col-6 m-auto text-center">