Add page taxonomy links for tags and categories

- Customizable text via _data file
- Enable/disable links by setting archive page filenames in _config.yml

_data/ui-text.yml

@@ -3,16 +3,18 @@
 # English (default)
 # -----------------
 en: &DEFAULT_EN
-  pagination_previous: "Previous"
-  pagination_next: "Next"
-  toc_label: "Overview"
-  ext_link_label: "Direct Link"
-  share_on: "Share on"
-  date_label: "Last Updated:"
-  related_label: "You May Also Enjoy"
-  follow_label: "Follow:"
-  feed_label: "Feed"
-  powered_by: "Powered by"
+  pagination_previous : "Previous"
+  pagination_next     : "Next"
+  toc_label           : "Overview"
+  ext_link_label      : "Direct Link"
+  share_on_label      : "Share on"
+  date_label          : "Last Updated:"
+  tags_label          : "Tags:"
+  categories_label    : "Categories:"
+  related_label       : "You May Also Enjoy"
+  follow_label        : "Follow:"
+  feed_label          : "Feed"
+  powered_by          : "Powered by"
 en_US:
   <<: *DEFAULT_EN
 en_UK: