redirects for the old tag urls

src/meta/tag-redirects.md

@@ -0,0 +1,12 @@
+---
+layout: tag-redirect.njk
+pagination:
+  data: collections
+  size: 1
+  alias: tag
+eleventyComputed:
+  permalink: /tag/{{ tag | slugify }}/
+  title: "this page has moved!"
+---
+
+If you're not automatically redirected, head to [the new URL for this tag](/tags/{{ tag | slugify }}/).