ci: add editorconfig

Author: OgeonX-Ai

.editorconfig

@@ -0,0 +1,10 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+trim_trailing_whitespace = false