Add EditorConfig to enforce spacing

Will automatically use the correct indenting and trim line endings on
supported IDEs.

.editorconfig

@@ -0,0 +1,14 @@
+# This file is for unifying the coding style for different editors and IDEs
+# editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = spaces
+indent_size = 2
+
+[*.md]
+trim_trailing_whitespace = true