feat: add completion_info_mode config option

src/config.zig

@@ -64,6 +64,7 @@ start_debugger_on_crash: bool = false,
 completion_trigger: CompletionTrigger = .automatic,
 completion_style: CompletionStyle = .dropdown,
 completion_insert_mode: CompletionInsertMode = .insert,
+completion_info_mode: CompletionInfoMode = .box,
 
 widget_style: WidgetStyle = .compact,
 palette_style: WidgetStyle = .bars_top_bottom,
@@ -206,6 +207,12 @@ pub const CompletionInsertMode = enum {
     replace,
 };
 
+pub const CompletionInfoMode = enum {
+    none,
+    box,
+    panel,
+};
+
 pub const Alignment = enum {
     left,
     right,