Add .editorconfig

Author: a-menshchikov

.editorconfig

@@ -0,0 +1,13 @@
+# editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+max_line_length = 100
+trim_trailing_whitespace = false