Add og-image thumb to template.

base.html

@@ -5,7 +5,7 @@
   <meta charset="utf-8" />
   <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 
-  {{- block "meta" . -}}
+  {{ block "meta" . -}}
     <title>
       {{- if eq .Data.PageType "/" }} {{- .L.T "global.siteName" -}}
       {{- else if eq .Data.PageType "glossary" }}{{- .L.Ts "public.glossary" "lang" (title .Data.Glossary.FromLang) -}}
@@ -20,8 +20,9 @@
       {{- else if ne .Data.Description "" }}{{ .Data.Description }}
       {{- else }}{{ block "description" . }}{{end}}
       {{- end -}}" />
-  {{- end -}}
+  {{- end }}
 
+  <meta property="og:image" content="{{ .Consts.RootURL }}/static/thumb.png">
   <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1" />
 	<script>
     window._ROOT_URL = "";