Add i18n for lightning footer link

frontend/src/app/lightning/lightning-dashboard/lightning-dashboard.component.html

@@ -98,10 +98,10 @@
     |
     <a [routerLink]="['/privacy-policy']" i18n="shared.privacy-policy|Privacy Policy">Privacy Policy</a>
     |
-    <a *ngIf="officialMempoolSpace" [routerLink]="['/lightning/group/the-mempool-open-source-project' | relativeUrl]">Connect to our nodes</a>
+    <a *ngIf="officialMempoolSpace" [routerLink]="['/lightning/group/the-mempool-open-source-project' | relativeUrl]" i18n="shared.connect-lightning-node|Link for users to see Lightning nodes run by mempool.space they can connect to">Connect to our nodes</a>
     <a *ngIf="!officialMempoolSpace" [routerLink]="['/tx/push' | relativeUrl]" i18n="shared.broadcast-transaction|Broadcast Transaction">Broadcast Transaction</a>
   </div>
 
   <br>
 
-</div>
+</div>