Add editorconfig file.

Author: nathan-mellis

.editorconfig

@@ -0,0 +1,17 @@
+# http://editorconfig.org
+
+root = true
+
+[*]
+indent_style = space
+indent_size = 4
+trim_trailing_whitespace = true
+insert_final_newline = true
+charset = utf-8
+
+[*.bat]
+indent_style = tab
+end_of_line = crlf
+
+[Makefile]
+indent_style = tab