Use i18n to translate some strings

Hugo 0.17 allows for easy multi-lingual sites. Strings can be
translated either in the theme or in the site, and missing strings
will fall back to the default language.

See: https://github.com/spf13/hugo/blob/master/docs/content/content/multilingual.md

layouts/_default/single.html

@@ -8,7 +8,7 @@
         {{ .Content }}
 
         {{ if .IsTranslated }}
-        <h4>Translations</h4>
+        <h4>{{ i18n "translations" }}</h4>
           <ul>
           {{ range .Translations }}
             <li>

layouts/_default/summary.html

@@ -4,5 +4,5 @@
     <p class="blog-post-meta"><time datetime="{{ .Date.Format "2006-01-02T15:04:05Z07:00" }}">{{ .Date.Format .Site.Params.date_format }}</time> by {{ .Params.author | default .Site.Params.author }}{{ if or (.Params.categories) (.Params.tags) }} in {{ partial "meta-terms.html" . }}{{ end }}</p>
   </header>
   {{ .Summary }}
-  <a href='{{ .Permalink }}'>Read more →</a>
+  <a href='{{ .Permalink }}'>{{ i18n "readMore" }} →</a>
 </article> <!-- /.blog-post -->