Use a better message for the InvalidBufferView (#36770)

Follow-up of https://github.com/zed-industries/zed/pull/36764

Release Notes:

- N/A

crates/workspace/src/invalid_buffer_view.rs

@@ -88,7 +88,7 @@ impl Render for InvalidBufferView {
                     v_flex()
                         .justify_center()
                         .gap_2()
-                        .child("Cannot display the file contents in Zed")
+                        .child(h_flex().justify_center().child("Unsupported file type"))
                         .when(self.is_local, |contents| {
                             contents.child(
                                 h_flex().justify_center().child(