Add external link feature for posts (#141)

* Add external link feature for posts

* Add post example using external link

CONTRIBUTORS.md

@@ -29,3 +29,4 @@
 - [Piotr Januszewski](https://piojanu.github.io)
 - [Artem Khvastunov](https://artspb.me)
 - [Gabriel Nepomuceno] (https://blog.nepomuceno.me)
+- [Salvatore Giordano] (https://salvatore-giordano.github.io)

archetypes/posts.md

@@ -6,4 +6,5 @@ description = ""
 slug = "" 
 tags = []
 categories = []
+externalLink = ""
 +++

exampleSite/content/posts/external-post.md

@@ -0,0 +1,14 @@
++++
+date = "2019-01-17"
+title = "Hugo coder wiki"
+slug = "hugo-coder-wiki"
+tags = [
+    "hugo",
+    "development",
+    "themes"
+]
+categories = [
+    "Development",
+]
+externalLink = "https://github.com/luizdepra/hugo-coder/wiki"
++++

layouts/posts/li.html

@@ -1,4 +1,4 @@
 <li>
   <span class="date">{{ .Date.Format (.Site.Params.dateFormat | default "January 2, 2006" ) }}</span>
-  <a class="title" href="{{ .URL }}">{{ .Title }}</a>
+  <a class="title" href="{{ .Params.ExternalLink | default .URL }}">{{ .Title }}</a>
 </li>