Add some more metadata for widgets + indieweb

- Add open graph metadata for other apps to display link previews
- Add more rel="me" metadata for the Indieweb. Getting on the Indieweb
  will take some time, but this is a good first step.

content/_index.gmi

@@ -2,6 +2,16 @@
 
 It me! This is the personal website of Seirdy (online handle), a.k.a. Rohan (meatspace).
 
+## Other versions of this site
+
+Canonical versions:
+=> gemini://seirdy.one Canonical Gemini capsule
+=> https://seirdy.one Canonical Web site
+
+Staging/rough-draft Tildeverse mirror:
+=> gemini://envs.net/~seirdy Tildeverse Gemini capsule
+=> https://envs.net/~seirdy Tildeverse Web site
+
 ## About me
 
 See the Director's Cut of my bio in the "about" page:

content/_index.md

@@ -14,9 +14,10 @@ It me! This is the personal website of Seirdy (online handle), a.k.a. Rohan
 Other versions of this website
 ------------------------------
 
-In addition to its [canonical URL](https://seirdy.one), a "rough draft" of this
+In addition to its <a href="https://seirdy.one" rel="me">canonical URL</a>, a "rough
-website also exists on my [Tildeverse page](https://envs.net/~seirdy) and on my
+draft" of this website also exists on my
-[Gemini space](gemini://seirdy.one).
+<a href="https://envs.net/~seirdy" rel="me">Tildeverse page</a> and on my
+<a href="gemini://seirdy.one" rel="me">Gemini space</a>
 
 About me
 --------
@@ -30,8 +31,10 @@ Git repos: <a href="https://sr.ht/~seirdy" rel="me">Sourcehut</a>,
 Contact
 -------
 
-Contact me via [email](mailto:seirdy@seirdy.one), or on the Fediverse via
+Contact me via <a href="mailto:seirdy@seirdy.one" rel="me">email</a>, or on the
-<a href="https://pleroma.envs.net/seirdy" rel="me">my Pleroma account</a>.
+Fediverse via <a href="https://pleroma.envs.net/seirdy" rel="me">my Pleroma
+account</a>.
 
 Chat with me: I prefer IRC, where my nick is usually Seirdy. Alternatively, I'm
-[@seirdy:envs.net](https://matrix.to/\#/@seirdy:envs.net) on Matrix.
+<a href="https://matrix.to/\#/@seirdy:envs.net" rel="me">@seirdy:envs.net</a> on
+Matrix.

themes/etch-custom/layouts/partials/head.html

@@ -33,11 +33,24 @@
 	{{ if .Params.highlight -}}
 	{{ $css_syntax := resources.Get "/css/syntax.css" | minify | resources.Fingerprint "sha384" }}
 	{{- printf `<link rel="stylesheet" href="%s" integrity="%s">` $css_syntax.RelPermalink $css_syntax.Data.Integrity | safeHTML }}
-	{{ end -}}
+	{{- end -}}
-
+	{{- if eq .RelPermalink "/" -}}
-	{{ if eq .RelPermalink "/" -}}
 	<title>{{ .Title }}</title>
-	{{ else -}}
+	{{- else -}}
 	<title>{{ .Title }} - Seirdy</title>
-	{{ end -}}
+	{{- end -}}
+	<!-- opengraph stuff; used in the Fediverse, Signal link previews, some
+	 RSS readers, and a certain large social media company -->
+	<meta property="og:title" content="{{ .Title }}">
+	<meta property="og:site_name" content="{{ $.Site.Title }}">
+	{{- if (eq "page" .Kind) }}
+	<meta property="og:type" content="article">
+	{{- else }}
+	<meta property="og:type" content="website">
+	{{- end }}
+	{{ printf `<meta property="og:image" content="%s">` $icon_192.Permalink | safeHTML }}
+	<meta property="og:image:type" content="image/png">
+	<meta property="og:image:height" content="192">
+	<meta property="og:image:width" content="192">
+	<meta property="og:url" content="https://seirdy.one{{ .RelPermalink }}"/>
 </head>