add tour to nav and pointer cursor for clickable tour cards

app/components/navigation.js

@@ -29,6 +29,11 @@ export default class Navigation extends Nanocomponent {
           title: "LBRY overview",
           url: "/overview"
         },
+        {
+          name: "Tour",
+          title: "Take a Tour",
+          url: "/tour"
+        },
         {
           name: "Resources",
           title: "View LBRY resources",

app/sass/pages/_tour.scss

@@ -185,6 +185,7 @@
   margin-bottom: 1rem;
   object-fit: contain;
   object-position: center;
+  cursor: pointer;
 
   &:not(:last-of-type) {
     margin-right: 1rem;