Add .editorconfig file

.editorconfig

@@ -0,0 +1,17 @@
+root = true
+
+[*]
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[CMakeLists.txt]
+end_of_line = lf
+indent_style = space
+indent_size = 4
+
+[*.{cpp,hpp,inl}]
+end_of_line = lf
+
+[*.md]
+trim_trailing_whitespace = false