fix menu memory, return memo button & add favicon

resources/js/views/Memo/MemoShow.vue

@@ -3,7 +3,7 @@
         <div v-if="loading" >> Loading...</div>
         <div v-else>
             <div class="flex-between flex-center mb-1">
-                <a href="#" class="link" @click="$router.back()">< Back</a>
+                <router-link to="/memos/" class="btn">< Back</router-link>
                 <div class="relative">
                     <router-link :to="'/memos/' + memo.memo_id + '/edit'" class="btn-secondary mr-1" >Edit</router-link>
                     <a href="#" class="btn-alert" @click="modal = ! modal">Delete</a>