binario/layouts/partials/post_thumbnail.html

{{- $img := (.page.Resources.ByType "image").GetMatch "thumbnail.*" }}
{{- $link := .link }}
{{- with $img }}
	<figure class="post__thumbnail thumbnail">
		{{- with $link }}
		<a class="thumbnail__link" href="{{ . }}">
			<img class="thumbnail__img" src="{{ $img.RelPermalink }}" alt="{{ $img.Title }}">
		</a>
		{{- else }}
			<img class="thumbnail__img" src="{{ $img.RelPermalink }}" alt="{{ $img.Title }}">
		{{- end }}
	</figure>
{{- end }}