Fix shift key not working for typing capital letters.

Was due to a change in crossterm's API behavior.

src/term_ui/mod.rs

@@ -373,6 +373,10 @@ impl TermUI {
                         code: KeyCode::Char(c),
                         modifiers: EMPTY_MOD,
                         ..
+                    } | KeyEvent {
+                        code: KeyCode::Char(c),
+                        modifiers: KeyModifiers::SHIFT,
+                        ..
                     }=> {
                         self.editor.insert_text_at_cursor(&c.to_string()[..]);
                     }