custom shortcode template for hugo to display a gravatar image inside a <figure> container. email address can be passed inside the shortcode or can be set inside the [params] group as "gravatarEmail"

gravatar.html

{{/*
	* The gravatar shortcode:
	* All arguments are optional, main ones are mail and size and have a fallback set in place.
	* Args:
	*		mail: [string] The email address. Falls back to .Site.Params.gravatarEmail which should be set in your config file.
	*		size: [int] The size of the fetched image. Defaults to 200 if not set.
	*		class: [string] The class to give to the figure block.
	*		link: [string] The address to link the picture to.
	*		target: [string] Where to open the link. One of "_blank", "_self", "_parent", "_top".
	*		caption: [string] Caption text to show with the image. Supports Markdown.
	*
	* Usage:
	*		{{< gravatar email="some@address.com" size=150 class="some class" link="https://example.com" target="_blank" caption="Here's a picture of a dog." >}}
	*
	* Output:
	*	<figure class="some class">
	*		<a href="https://example.com" target="_blank">
	*			<img src="https://www.gravatar.com/avatar/emailhash?s=150" alt="Here's a picture of a dog." />
	*		</a>
	*		<<figcaption>
	*			<p>
	*				Here's a picture of a dog.
	*			</p>
	*		</figcaption>
	*	</figure>
	*
	*/}}
{{- if .Get "mail" -}}
	{{- $mailaddr := .Get "mail" -}}
	{{- .Scratch.Set "mailhash" $mailaddr -}}
{{ else }}
	{{- .Scratch.Set "mailhash" $.Site.Params.gravatarEmail -}}
{{ end }}
{{- $hash := .Scratch.Get "mailhash" | lower | md5 -}}

<figure{{ with .Get "class" }} class="{{ . }}"{{ end }}>
{{- if .Get "link" -}}
	<a href="{{ .Get "link" }}"{{ with .Get "target" }} target="{{ . }}"{{ end }}{{ with .Get "rel" }} rel="{{ . }}"{{ end }}>
{{- end }}
	<img src="https://www.gravatar.com/avatar/{{- $hash -}}?s={{- with .Get "size" }}{{.}}{{ else }}200{{ end }}"
		{{- if or (.Get "alt") (.Get "caption") }}
		alt="{{ with .Get "alt" }}{{ . }}{{ else }}{{ .Get "caption" | markdownify| plainify }}{{ end }}"
		{{- end -}}
	/>
{{- if .Get "link" -}}
	</a>
{{- end }}
{{- if .Get "caption" -}}
	<figcaption>
		<p>
		{{- .Get "caption" | markdownify -}}
		</p>
	</figcaption>
{{- end }}
</figure>