Set page title for networks and tags overviews.

assets/components/networks/networks.vue

@@ -20,6 +20,7 @@ import Network from '../tile/network.vue';
 
 async function mounted() {
     this.networks = await this.$store.dispatch('fetchNetworks');
+    this.pageTitle = 'Networks';
 }
 
 function siteCount() {
@@ -33,6 +34,7 @@ export default {
     data() {
         return {
             networks: [],
+            pageTitle: null,
         };
     },
     computed: {