feat: hack completion display

always show all candidates as if show-all-if-ambiguous is on

doc/arif.texi

@@ -274,8 +274,6 @@ configure the key bindings from a Readline init file.
 Here is an example @code{~/.inputrc} snippet:
 
 @example
-set show-all-if-ambiguous on
-
 "\e ":     arify-toggle
 "\e\b":    arify-next-engine
 "\e[5;3~": arify-page-up    # M-PgUp

src/arif_rl.c

@@ -108,6 +108,12 @@ arif_rl_complete(
         assert(match != NULL);
         match[0] = '\0';
         comp_list[0] = match;
+
+        // This hack ensures that candidates are always displayed,
+        // even without `show-all-if-ambiguous` on.
+        if (rl_completion_type == TAB) {
+            arif_rl_display(ctx, NULL, num, 0);
+        }
     }
 
     return comp_list;