Add Create Thumbnail Image For A PDF as a ruby til

Author: jbranchaud

README.md

@@ -7,7 +7,7 @@ variety of languages and technologies. These are things that don't really
 warrant a full blog post. These are mostly things I learn by pairing with
 smart people at [Hashrocket](http://hashrocket.com/).
 
-_339 TILs and counting..._
+_340 TILs and counting..._
 
 ---
 
@@ -236,6 +236,7 @@ _339 TILs and counting..._
 - [Comparing Arrays In RSpec](ruby/comparing-arrays-in-rspec.md)
 - [Construct A Constant From A String](ruby/construct-a-constant-from-a-string.md)
 - [Create an Array of Stringed Numbers](ruby/create-an-array-of-stringed-numbers.md)
+- [Create Thumbnail Image For A PDF](ruby/create-thumbnail-image-for-a-pdf.md)
 - [Defaulting To Frozen String Literals](ruby/defaulting-to-frozen-string-literals.md)
 - [Destructuring Arrays In Blocks](ruby/destructuring-arrays-in-blocks.md)
 - [Disassemble Some Codes](ruby/disassemble-some-codes.md)

ruby/create-thumbnail-image-for-a-pdf.md

@@ -0,0 +1,18 @@
+# Create Thumbnail Image For A PDF
+
+The [`rmagick`](https://rmagick.github.io/) gem is a wrapper around the
+[ImageMagick](http://www.imagemagick.org/script/index.php) software suite.
+This gem can be used to create a thumbnail image of a PDF using the
+following snippet of code.
+
+```ruby
+require 'rmagick'
+pdf = Magick::ImageList.new('document.pdf')
+first_page = pdf.first
+scaled_page = first_page.scale(300, 450)
+scaled_page.write('document-thumbnail.jpg')
+```
+
+The scale can be adjust as necessary to the use case.
+
+[source](http://stackoverflow.com/questions/65250/convert-a-doc-or-pdf-to-an-image-and-display-a-thumbnail-in-ruby)