user mention (#3771)

src/client/app/desktop/views/pages/user/user.header.vue

@@ -36,6 +36,7 @@
 			<span class="notes-count"><b>{{ user.notesCount | number }}</b>{{ $t('posts') }}</span>
 			<router-link :to="user | userPage('following')" class="following clickable"><b>{{ user.followingCount | number }}</b>{{ $t('following') }}</router-link>
 			<router-link :to="user | userPage('followers')" class="followers clickable"><b>{{ user.followersCount | number }}</b>{{ $t('followers') }}</router-link>
+			<button @click="mention" :title="$t('mention')"><fa icon="at"/></button>
 		</div>
 	</div>
 </div>
@@ -77,6 +78,9 @@ export default Vue.extend({
 		}
 	},
 	methods: {
+		mention() {
+			this.$post({ mention: this.user });
+		},
 		onScroll() {
 			const banner = this.$refs.banner as any;