fix post pagination without post titles

i18n/en.yaml

@@ -54,3 +54,9 @@ readNext:
 
 lastMod:
   other: "Last modified:"
+
+toNewPost:
+  other: "to new post"
+
+toOldPost:
+  other: "to old post"

i18n/ru.yaml

@@ -51,3 +51,9 @@ readNext:
 
 lastMod:
   other: "Отредактировано:"
+
+toNewPost:
+  other: "к новой записи"
+
+toOldPost:
+  other: "к старой записи"

layouts/partials/post-pagination.html

@@ -1,13 +1,15 @@
 {{ if or ( .PrevInSection ) ( .NextInSection ) }}
+    {{ $toNewPostMessage := i18n "toNewPost" }}
+    {{ $toOldPostMessage := i18n "toOldPost" }}
     <div class="pagination post-pagination">
         <div class="left pagination-item {{ if not .NextInSection }}disabled{{ end }}">
             {{ if .NextInSection }}
-                <a href="{{ .NextInSection.RelPermalink }}">{{ .NextInSection.Title }}</a>
+                <a href="{{ .NextInSection.RelPermalink }}">{{ .NextInSection.Title | default $toNewPostMessage }}</a>
             {{ end }}
         </div>
         <div class="right pagination-item {{ if not .PrevInSection }}disabled{{ end }}">
             {{ if .PrevInSection }}
-                <a href="{{ .PrevInSection.RelPermalink }}">{{ .PrevInSection.Title }}</a>
+                <a href="{{ .PrevInSection.RelPermalink }}">{{ .PrevInSection.Title | default $toOldPostMessage }}</a>
             {{ end }}
         </div>
     </div>