Add 404 design

messages/en/pages/notFoundPage.json

@@ -0,0 +1,9 @@
+{
+  "_comment": "Global 404 — Figma 22078-808557",
+  "codeTitle": "404",
+  "heading": "Page not found",
+  "description": "Looks like this page didn't make it to a consensus. It may have moved, been removed, or never existed.",
+  "goHomeCta": "Go back home",
+  "browseTemplatesCta": "Browse templates",
+  "templateHint": "Maybe one of these templates can help?"
+}