fix: fix(sharing): use small Twitter card for small images

This commit fixes 929d500d4456871e0732a22f3861f3ee067b2755

Fix #813

layouts/partials/header.html

@@ -127,14 +127,14 @@
   {{ if $featured_image }}
     {{ $og_image = $featured_image.Permalink }}
   {{ else if .Params.header.image }}
-    {{ $og_image = .Params.header.image }}
+    {{ $og_image = printf "img/%s" .Params.header.image | absURL }}
   {{ else if .Site.Params.sharing_image }}
-    {{ $og_image = .Site.Params.sharing_image }}
+    {{ $og_image = printf "img/%s" .Site.Params.sharing_image | absURL }}
   {{ else if .Site.Params.avatar }}
     {{ $og_image = (printf "img/%s" $.Site.Params.avatar) | absURL }}
     {{ $twitter_card = "summary" }}
   {{ else }}
-    {{ $og_image = "icon-192.png" }}
+    {{ $og_image = "img/icon-192.png" | absURL }}
     {{ $twitter_card = "summary" }}
   {{ end }}
   <meta property="twitter:card" content="{{ $twitter_card }}">
@@ -146,7 +146,7 @@
   <meta property="og:url" content="{{ .Permalink }}">
   <meta property="og:title" content="{{ if not .IsHome }}{{ .Title }} | {{ end }}{{ .Site.Title }}">
   <meta property="og:description" content="{{ $desc }}">
-  {{- with $og_image }}<meta property="og:image" content="{{ printf "img/%s" . | absURL }}">{{end}}
+  {{- with $og_image }}<meta property="og:image" content="{{ . }}">{{end}}
   <meta property="og:locale" content="{{ .Site.LanguageCode | default "en-us" }}">
   {{ if .IsPage }}
   {{ if not .PublishDate.IsZero }}<meta property="article:published_time" content="{{ .PublishDate.Format "2006-01-02T15:04:05-07:00" | safeHTML }}">