When I write a document in LibreOffice (or any other office suite), it should be possible to pick your desired style guide. Here's a few popular names.
1. The Chicago Manual of Style
2. AP Style
3. APA Manual
4. New Oxford Style Manual
5. MLA Handbook
6. AMA Manual of Style
Do you include spaces around em dashes? Should you rock a serial comma in lists? The style guide you follow should set the grammar check to do the right thing.