docs(readme): add a note that shift+↑/↓ may not work in all terminals

#3

Author: preiter93

README.md

@@ -56,7 +56,7 @@ Download from [GitHub Releases](https://github.com/preiter93/tuigram/releases)
 | `h/l` or `←/→` | Navigate left/right (participants) |
 | `j/k` or `↓/↑` | Navigate down/up (events) |
 | `H/L` or `Shift+←/→` | Move participant left/right, reverse event arrow |
-| `J/K` or `Shift+↓/↑` | Move event up/down |
+| `J/K` or `Shift+↓/↑` | Move event up/down* |
 | `Enter` | Edit selected |
 | `r` | Rename selected |
 | `d` | Delete selected |
@@ -65,6 +65,8 @@ Download from [GitHub Releases](https://github.com/preiter93/tuigram/releases)
 | `?` | Help |
 | `Ctrl+c` | Quit |
 
+> \* `Shift+↑/↓` may not work in all terminals, some intercept these for scrollback. Use `J`/`K` instead.
+
 ## Mermaid
 
 ### Export

src/app.rs

@@ -214,7 +214,6 @@ fn global_keybindings(world: &mut World) {
         let event_count = diagram.event_count();
         let selection = world.get::<EditorState>().selection;
 
-        // Remember participant index before moving to events
         if let Selection::Participant(idx) = selection {
             world.get_mut::<EditorState>().last_participant_index = Some(idx);
         }