Flag German-style comma usage (excess commas)

When writing English text, bilingual German speakers often bring over German punctuation rules. Specifically, they tend to add commas before subordinate clauses, relative clauses, or conjunctions where they are grammatically incorrect in English.

It would be great if Harper could identify and flag these excess commas to improve English writing for German speakers

Example:
- One of the things, that really bothers me is the deep chasm between the synchronous world and the asynchronous world - it is one way only

No file or test is named in the issue. Start by locating Harper's existing punctuation or comma rules, then use the provided sentence to understand the intended German-style excess-comma case; done means incorrect commas before subordinate or relative clauses and conjunctions are flagged without disrupting valid English punctuation.

Written by the indexing model from the issue text.