Add example on setting Hugo section in a parent subtree

Closes https://github.com/kaushalmodi/ox-hugo/issues/31

This feature was enabled by adding property inheritance support in
1a0d26ca22

example-site/content-org/all-posts.org

@@ -295,6 +295,26 @@ Here the front matter format is set to YAML using the
 =HUGO_FRONT_MATTER_FORMAT= key in property drawer.
 
 Here there is white space in menu name property.
+* Articles
+:PROPERTIES:
+:EXPORT_HUGO_SECTION: articles
+:END:
+** Article 1
+:PROPERTIES:
+:EXPORT_FILE_NAME: article-1
+:END:
+First article.
+
+This will land in =content/articles/= as the parent of this subtree
+sets =EXPORT_HUGO_SECTION= to =articles=. Note that the theme needs to
+define at least the =single.html= for =articles/=.
+** Article 2
+:PROPERTIES:
+:EXPORT_FILE_NAME: article-2
+:END:
+Second article.
+
+This will also land in =content/articles/= the same way.
 * TODO Pre-Draft State
 :PROPERTIES:
 :EXPORT_FILE_NAME: draft-state-todo

example-site/content/articles/article-1.md

@@ -0,0 +1,10 @@
++++
+title = "Article 1"
+date = 2017-07-19T08:34:29-04:00
+tags = []
+draft = false
++++
+
+First article.
+
+This will land in `content/articles/` as the parent of this subtree sets `EXPORT_HUGO_SECTION` to `articles`. Note that the theme needs to define at least the `single.html` for `articles/`.

example-site/content/articles/article-2.md

@@ -0,0 +1,10 @@
++++
+title = "Article 2"
+date = 2017-07-19T08:34:22-04:00
+tags = []
+draft = false
++++
+
+Second article.
+
+This will also land in `content/articles/` the same way.

example-site/themes/bare_min/layouts/articles/single.html

@@ -0,0 +1,8 @@
+{{ define "main" }}
+
+<div class="article">
+    <h1 class="article-title">{{ .Title }}</h1>
+    {{ .Content }}
+</div>
+
+{{ end }}