arrow

GH-36095: [Go] Add doc for `pqarrow.FileWriter.WriteBuffered` (#36163)

### Rationale for this change

Docs to help people decide on the best-performing option.

### What changes are included in this PR?

Doc change only.

### Are these changes tested?

N/A

### Are there any user-facing changes?

Doc

* Closes: #36095

Authored-by: candiduslynx <candiduslynx@gmail.com>
Signed-off-by: Matt Topol <zotthewizard@gmail.com>