Add /.editorconfig file

The addition of the `/.editorconfig` file is made in order to
encourage and help developers and their teams define and maintain
consistent coding styles between their different editors and IDEs.

By default, the `/.editorconfig` file includes some default
properties that apply to the coding styles used by HTML5 Boilerplate,
but users can easily change them to better suit their needs.

Since users need to install a editor/IDE plugin in order for the
properties from the `/.editorconfig` to be applied, we were reluctant
to add this file in the past (see: #1124).
Nowadays however, the EditorConfig project provides plugins for most
of the popular editors/IDEs (see: http://editorconfig.org/#download),
plus, more and more developers are using it.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Ref: http://editorconfig.org/

Close: #1561
       #1564

.editorconfig

@@ -0,0 +1,13 @@
+# editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 4
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+trim_trailing_whitespace = false

CHANGELOG.md

@@ -1,5 +1,8 @@
 ### HEAD
 
+* Add `/.editorconfig` file
+  ([#1561](https://github.com/h5bp/html5-boilerplate/issues/1561),
+   [#1564](https://github.com/h5bp/html5-boilerplate/issues/1564)).
 * Add `auto` to the Google Universal Analytics tracker create method
   ([#1562](https://github.com/h5bp/html5-boilerplate/issues/1562)).
 * Add `timeline` and `timelineEnd` to the list of `console` methods

doc/misc.md

@@ -4,6 +4,7 @@ table of contents](TOC.md)
 # Miscellaneous
 
 * [.gitignore](#gitignore)
+* [.editorconfig](#editorconfig)
 * [.htaccess](#htaccess)
 * [crossdomain.xml](#crossdomainxml)
 
@@ -32,6 +33,32 @@ globally ignore:
 * Comprehensive set of ignores on GitHub: https://github.com/github/gitignore
 
 
+## .editorconfig
+
+HTML5 Boilerplate includes an `.editorconfig` file that helps you and your team
+define and maintain consistent coding styles between different editors and IDEs.
+EditorConfig files are easily readable and they work nicely with version control
+systems.
+
+When opening any file, your IDE’s EditorConfig plugin will look for a file named
+`.editorconfig` in the directory of the opened file and in every parent
+directory until the root filepath is reached or an EditorConfig file with
+`root = true` is found.
+
+The EditorConfig file provided by this project will inform your IDE to follow
+our current practices, which include UTF-8 charset encoding, use of the line
+feed character for line breaks, use of four space characters for indentations,
+the removal of any whitespace characters preceding newline characters, and the
+presence of a final line break character at the end of files.
+
+If you will not be using a server configuration file provided by this project,
+remember to block access to `.editorconfig` files, as they may disclose
+sensitive information.
+
+* [EditorConfig homepage](http://editorconfig.org/)
+* [Download IDE Plugin](http://editorconfig.org/#download)
+
+
 ### `.htaccess`
 
 A `.htaccess` (hypertext access) file is a Apache HTTP server configuration