Add EditorConfig file to blueprints

As discussed in #1426, EditorConfig file is added to blueprints. I have set defaults for html, css, js and hbs files and they can be modified if needed. The default is 2 space indents for all of them. Please take a look.

cc @abuiles @treyhunner @ccoenen
EditorConfig sections cascade, so these indentation specifications are redundant unless there are files in the repository besides js, hbs, css, and html.  The sections below could have been left out or the `indent_style = space` could have been left off.