Add internationalization support (#738)

locales/en-US/index.json

@@ -0,0 +1,17 @@
+{
+  "frog": {
+    "message": "You've been frogged! 🐸"
+  },
+  "frog.altText": {
+    "message": "A photorealistic painting of a frog labyrinth"
+  },
+  "frog.froggedPeople": {
+    "message": "{count, plural, one {{count} more person} other {{count} more people}} were also frogged!"
+  },
+  "frog.sinceOpened": {
+    "message": "This page was opened {ago}"
+  },
+  "frog.title": {
+    "message": "Frog"
+  }
+}

locales/en-US/languages.json

@@ -0,0 +1,3 @@
+{
+  "en-US": "American English"
+}

locales/en-US/meta.json

@@ -0,0 +1,6 @@
+{
+  "displayName": {
+    "description": "The name of the language in dialect form (e.g. Français canadien for French spoken in Canada, not French (Canada))",
+    "message": "American English"
+  }
+}