minor: Add basic editorconfig and pre-commit hooks to enforce style for whitespaces (#1926)

benchmark/tip_suggestion/topic.jsonl

@@ -47,4 +47,4 @@
 {"topic": "self-publishing a book", "number": 7}
 {"topic": "starting an urban farm", "number": 6}
 {"topic": "improving your memory", "number": 8}
-{"topic": "creating a personal brand online", "number": 9}
+{"topic": "creating a personal brand online", "number": 9}