Add trailing slash to remove redirects. (#112)

* Add trailing slash to remove redirects.

When you request /tags/foo, the web server will redirect you to
/tags/foo/ so the browser needs to make two requests.  Add the trailing
slash in the link so that only one request is needed.

* Add trailing slash to remove redirects.

* Improve how trailing slash is added.

Co-Authored-By: tobinjt <johntobin@johntobin.ie>

* Improve how trailing slash is added.

Co-Authored-By: tobinjt <johntobin@johntobin.ie>

* Add John Tobin.

CONTRIBUTORS.md

@@ -24,3 +24,4 @@
 - [Joseph Ting](https://github.com/josephting)
 - [Abner Campanha](https://github.com/abnerpc)
 - [Martin Kiesel](https://github.com/Kyslik)
+- [John Tobin](https://www.johntobin.ie/)

layouts/partials/taxonomy/categories.html

@@ -4,6 +4,6 @@
     {{- if gt $index 0 }}
       <span class="separator">•</span>
     {{- end }}
-    <a href="{{ ( print "categories/" ( . | urlize ) ) | relLangURL }}">{{ . }}</a>
+    <a href="{{ ( printf "categories/%s/" ( . | urlize ) ) | relLangURL }}">{{ . }}</a>
   {{- end -}}
 </div>

layouts/partials/taxonomy/tags.html

@@ -4,6 +4,6 @@
     {{- if gt $index 0 }}
       <span class="separator">•</span>
     {{- end }}
-    <a href="{{ ( print "tags/" ( . | urlize ) ) | relLangURL }}">{{ . }}</a>
+    <a href="{{ ( printf "tags/%s/" ( . | urlize ) ) | relLangURL }}">{{ . }}</a>
   {{- end -}}
 </div>