Add basic scaffolding for site.

themes/mainroad/.editorconfig

@@ -0,0 +1,19 @@
+# editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+indent_style = tab
+end_of_line = lf
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.{json,yaml,yml,toml,md,babelrc,eslintrc,postcssrc,stylelintrc}]
+indent_style = space
+indent_size = 2
+
+[layouts/**.{html,svg}]
+insert_final_newline = false