Run formatter from Document directory (#12315)

Co-authored-by: Rob Gonnella <rob.gonnella@papayapay.com>

helix-view/src/document.rs

@@ -774,7 +774,13 @@ impl Document {
         {
             use std::process::Stdio;
             let text = self.text().clone();
+
             let mut process = tokio::process::Command::new(&fmt_cmd);
+
+            if let Some(doc_dir) = self.path.as_ref().and_then(|path| path.parent()) {
+                process.current_dir(doc_dir);
+            }
+
             process
                 .args(fmt_args)
                 .stdin(Stdio::piped())