Add packaging summit to menu and footer

Author: hypha

src/data/links.json

@@ -72,6 +72,10 @@
           "name": "Rust Summit",
           "path": "/session/rust-summit"
         },
+        {
+          "name": "Packaging Summit",
+          "path": "/session/packaging-summit"
+        },        
         {
           "name": "Sprints Weekend",
           "path": "/sprints"
@@ -261,6 +265,10 @@
           "name": "Rust Summit",
           "path": "/session/rust-summit"
         },
+        {
+          "name": "Packaging Summit",
+          "path": "/session/packaging-summit"
+        },         
         {
           "name": "Sprints Weekend",
           "path": "/sprints"