add default author (#408)

exampleSite/config.toml

@@ -27,6 +27,7 @@ enableRobotsTXT = true
   filename = "sitemap.xml"
 
 [params]
+  author = ""
   favicon = ""
   site_logo = ""
   description = "The last theme you'll ever need. Maybe."
@@ -44,4 +45,4 @@ enableRobotsTXT = true
   # choose a background color from any on this page: http://tachyons.io/docs/themes/skins/ and preface it with "bg-"
   background_color_class = "bg-black"
   featured_image = "/images/gohugo-default-sample-hero-image.jpg"
-  recent_posts_number = 2
+  recent_posts_number = 2

layouts/_default/single.html

@@ -18,7 +18,7 @@
       <h1 class="f1 athelas mt3 mb1">
         {{- .Title -}}
       </h1>
-      {{ with .Params.author }}
+      {{ with .Params.author | default .Site.Params.author }}
       <p class="tracked">
           By <strong>
           {{ if reflect.IsSlice . }}