Set defaults for _posts

- layout ~> post.html
- enable comments

_posts/2011-03-10-sample-post.md

@@ -1,10 +1,9 @@
 ---
-layout: post
 title: Sample Post
 excerpt: "Just about everything you'll need to style in the theme: headings, paragraphs, blockquotes, tables, code blocks, and more."
 modified: 2013-05-31
 tags: [intro, beginner, jekyll, tutorial]
-comments: true
+comments: false
 image:
   feature: sample-image-5.jpg
   credit: WeGraphics

_posts/2012-05-22-readability-post.md

@@ -1,9 +1,7 @@
 ---
-layout: post
 title: "Testing Readability with a Bunch of Text"
 excerpt: "A ton of text to test readability."
 tags: [sample post, readability, test]
-comments: true
 ---
 
 Portland in shoreditch Vice, labore typewriter pariatur hoodie fap sartorial Austin. Pinterest literally occupy Schlitz forage. Odio ad blue bottle vinyl, 90's narwhal commodo bitters pour-over nostrud. Ugh est hashtag in, fingerstache adipisicing laboris esse Pinterest shabby chic Portland. Shoreditch bicycle rights anim, flexitarian laboris put a bird on it vinyl cupidatat narwhal. Hashtag artisan skateboard, flannel Bushwick nesciunt salvia aute fixie do plaid post-ironic dolor McSweeney's. Cliche pour-over chambray nulla four loko skateboard sapiente hashtag.

_posts/2013-05-22-sample-post-images.md

@@ -1,9 +1,7 @@
 ---
-layout: post
 title: "A Post with Images"
 excerpt: "Examples and code for displaying images in posts."
 tags: [sample post, images, test]
-comments: true
 ---
 
 Here are some examples of what a post with images might look like. If you want to display two or three images next to each other responsively use `figure` with the appropriate `class`. Each instance of `figure` is auto-numbered and displayed in the caption.

_posts/2013-05-23-readability-feature-post.md

@@ -1,9 +1,7 @@
 ---
-layout: post
 title: "Post with Large Feature Image and Text"
 excerpt: "Custom written post descriptions are the way to go... if you're not lazy."
 tags: [sample post, readability, test]
-comments: true
 image:
   feature: sample-image-4.jpg
   credit: WeGraphics

_posts/2013-08-12-sample-link-post.md

@@ -1,10 +1,8 @@
 ---
-layout: post
 title: "Sample Link Post"
 excerpt: "Example and code for using link posts."
 tags: [sample post, link post]
 link: http://mademistakes.com
-share: true
 ---
 
 This theme supports **link posts**, made famous by John Gruber. To use, just add `link: http://url-you-want-linked` to the post's YAML front matter and you're done.

_posts/2013-08-16-code-highlighting-post.md

@@ -1,10 +1,8 @@
 ---
-layout: post
 title: Syntax Highlighting Post
 excerpt: "Demo post displaying the various ways of highlighting code in Markdown."
 tags: [sample post, code, highlighting]
 modified: 2016-02-01
-comments: true
 ---
 
 Syntax highlighting is a feature that displays source code, in different colors and fonts according to the category of terms. This feature facilitates writing in a structured language such as a programming language or a markup language as both structures and syntax errors are visually distinct. Highlighting does not affect the meaning of the text itself; it is intended only for human readers.[^1]

_posts/2014-07-31-author-override.md

@@ -1,5 +1,4 @@
 ---
-layout: post
 title: "Author Override"
 author: billy_rick
 modified: