Allow certain pages to not be indexed by SE

Fixes #499

Author: regisphilibert

README.md

@@ -187,6 +187,10 @@ Here is the list of built-in services. Those marked with an `*` are also part of
 
 In order to add an unkown service (absent from the list above), you simply need to add all three settings to `ananke_socials`: name, url, label, color, and optionally add an icon file matching the `name` to the `assets/ananke/socials` directory. In the absence of an icon, the theme will print the service's label.
 
+### Content indexing
+
+If the theme is ran in [production](#production), pages will be indexed by search engines. To prevent indexing on some given pages, add `private: true` to its Front Matter.
+
 ### Update font or body classes
 
 The theme is set, by default, to use a near-white background color and the "Avenir" or serif typeface. You can change these in your config file with the `body_classes` parameter, like this:

layouts/_default/baseof.html

@@ -9,10 +9,12 @@
     <meta name="description" content="{{ with .Description }}{{ . }}{{ else }}{{if .IsPage}}{{ .Summary }}{{ else }}{{ with .Site.Params.description }}{{ . }}{{ end }}{{ end }}{{ end }}">
     {{ hugo.Generator }}
     {{/* NOTE: For Production make sure you add `HUGO_ENV="production"` before your build command */}}
-    {{ if eq (getenv "HUGO_ENV") "production" | or (eq .Site.Params.env "production")  }}
-      <META NAME="ROBOTS" CONTENT="INDEX, FOLLOW">
+    {{ $production := eq (getenv "HUGO_ENV") "production" | or (eq site.Params.env "production") }}
+    {{ $public := not .Params.private }}
+    {{ if and $production $public }}
+      <meta name="robots" content="index, follow">
     {{ else }}
-      <META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">
+      <meta name="robots" content="noindex, nofollow">
     {{ end }}
 
     {{ partial "site-style.html" . }}