vim: Add g? convert to Rot13/Rot47 (#27824)

Release Notes:

- Added `g?` convert to `Rot13`/`Rot47`

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/gpui/src/keymap/context.rs

@@ -412,7 +412,7 @@ fn is_identifier_char(c: char) -> bool {
 }
 
 fn is_vim_operator_char(c: char) -> bool {
-    c == '>' || c == '<' || c == '~' || c == '"'
+    c == '>' || c == '<' || c == '~' || c == '"' || c == '?'
 }
 
 fn skip_whitespace(source: &str) -> &str {