Merge pull request #5941 from jekyll/3.4.2.release.post

Add v3.4.2 release post

docs/_posts/2017-03-09-jekyll-3-4-2-released.markdown

@@ -0,0 +1,51 @@
+---
+title: 'Jekyll 3.4.2 Released'
+date: 2017-03-09 15:41:57 -0500
+author: parkr
+version: 3.4.2
+categories: [release]
+---
+
+Another one-PR patch update, though without the same [lessons as for the
+previous release]({% link _posts/2017-03-02-jekyll-3-4-1-released.markdown %}).
+
+This release includes a beneficial change for a number of plugins:
+**static files now respect front matter defaults**.
+
+You might be asking yourself: "why would static files, files that are
+static files explicitly because they *don't* have YAML front matter, want
+to respect YAML front matter?" That's a great question. Let me illustrate
+with an example.
+
+Let's look at `jekyll-sitemap`. This plugin generates a list of documents,
+pages, and static files, and some metadata for them in an XML file for a
+Google/Yahoo/Bing/DuckDuckGo crawler to consume. If you don't want a given
+file in this list, you set `sitemap: false` in the YAML front matter. But
+what about static files, which don't have YAML front matter? Before this
+release, they could not be excluded because they had no properties in YAML
+other than [the ones we explicitly assigned](https://github.com/jekyll/jekyll/blob/v3.4.1/lib/jekyll/static_file.rb#L98-L106).
+So if you had a PDF you didn't want to be in your sitemap, you couldn't use
+`jekyll-sitemap`.
+
+With this release, you can now set [front matter
+defaults](/docs/configuration/#front-matter-defaults) for static files:
+
+```yaml
+defaults:
+  -
+    scope:
+      path: "pdfs/"
+    values:
+      sitemap: false
+```
+
+Now, for every file in the Liquid `site.static_files` loop which is in the
+folder `pdfs/`, you'll see `sitemap` equal to `false`.
+
+Many thanks to @benbalter for coming up with the solution and ensuring
+sitemaps everywhere are filled with just the right content.
+
+As always, if you notice any bugs, please search the issues and file one if
+you can't find another related to your issue.
+
+Happy Jekylling!