Add a label to codelines that includes the source file.

themes/vanilla/layouts/shortcodes/codelines.html

@@ -11,4 +11,8 @@
 {{ else }}
 {{ .Scratch.Set "opts" "" }}
 {{ end }}
-{{ highlight (delimit $v "\n") (.Get 0) (printf "linenos=table,linenostart=%d%s" (.Get 2) (.Scratch.Get "opts")) }}
+<div class="highlight-group">
+    <div class="highlight-label">From <a href="https://dev.danilafe.com/Web-Projects/blog-static/src/branch/master/code/{{ .Get 1 }}">{{ path.Base (.Get 1) }}</a>,
+        {{ if eq (.Get 2) (.Get 3) }}line {{ .Get 2 }}{{ else }} lines {{ .Get 2 }} through {{ .Get 3 }}{{ end }}</div>
+    {{ highlight (delimit $v "\n") (.Get 0) (printf "linenos=table,linenostart=%d%s" (.Get 2) (.Scratch.Get "opts")) }}
+</div>