Move content-*.php into subfolder

Hi everyone, 
I'm new user of Underscore so I don't know if you already discus this before:

In order to tidy up a bit the theme root folder, I've created "templates" folder and moved there all content-*.php files.
The inclusion of these files inside theme don't change a lot...they will be included according to the get_template_part usage for subfolders (http://codex.wordpress.org/Function_Reference/get_template_part#Using_with_theme_subfolders).

So the new structure will be the following:

```
root
  |_ templates
     |_ content-single.php
     |_ content-page.php
     |_ content-custom-post-type.php

|_ single.php
|_ page.php
|_ post-type.php
```
Also, this folder can be used for other template parts, like comments, page title...avoiding code duplications.

This is just a proposal, maybe I'm an order maniac :) ...but I found this template structure useful for complex projects with many post types or formats

Cheers!