Only canonicalize alphabetic keys

The Kitty keyboard protocol separates out the shift modifier for a
bunch of these keys, I think based on default english keyboard
layouts (?).

This is a little mind-bending since I get an `A-S-9` key event when
I press `A-)` on my keyboard but my keyboard is mapped so that this
particular chord doesn't include shift.

This most likely isn't all of the keys that need to be remapped in the
default keymap. Perhaps we can do some magic in `canonicalize_key` to
match the expected keys?

helix-term/src/keymap/default.rs

@@ -185,8 +185,8 @@ pub fn default() -> HashMap<Mode, Keymap> {
 
         "(" => rotate_selections_backward,
         ")" => rotate_selections_forward,
-        "A-(" => rotate_selection_contents_backward,
-        "A-)" => rotate_selection_contents_forward,
+        "A-(" | "A-S-9" => rotate_selection_contents_backward,
+        "A-)" | "A-S-0" => rotate_selection_contents_forward,
 
         "A-:" => ensure_selections_forward,
 
@@ -329,7 +329,7 @@ pub fn default() -> HashMap<Mode, Keymap> {
         "|" => shell_pipe,
         "A-|" => shell_pipe_to,
         "!" => shell_insert_output,
-        "A-!" => shell_append_output,
+        "A-!" | "A-S-1" => shell_append_output,
         "$" => shell_keep_pipe,
         "C-z" => suspend,
 

helix-term/src/ui/editor.rs

@@ -1641,11 +1641,11 @@ impl Component for EditorView {
 }
 
 fn canonicalize_key(key: &mut KeyEvent) {
-    if let KeyEvent {
-        code: KeyCode::Char(_),
-        modifiers: _,
-    } = key
-    {
-        key.modifiers.remove(KeyModifiers::SHIFT)
+    match key {
+        KeyEvent {
+            code: KeyCode::Char(char),
+            modifiers: _,
+        } if char.is_alphabetic() => key.modifiers.remove(KeyModifiers::SHIFT),
+        _ => (),
     }
 }