Add scrolling actions and board widget

Introduce directional and scroll actions, update keybindings, add
scrollbar
state to SkirmishState, and render the board with a new BoardWidget.
Adjust CLI
defaults and layout heights accordingly.

src/app/views/skirmish.rs

@@ -1,4 +1,8 @@
-use crate::app::{App, keybindings::Action, widgets::KeybindingsWidget};
+use crate::app::{
+    App,
+    keybindings::Action,
+    widgets::{BoardWidget, KeybindingsWidget},
+};
 use ratatui::{
     buffer::Buffer,
     layout::{Alignment, Constraint, Layout, Margin, Rect},
@@ -11,7 +15,7 @@ pub fn skirmish_view(app: &App, area: Rect, buf: &mut Buffer) {
     let vertical_layout: Layout = Layout::vertical([
         Constraint::Length(4),
         Constraint::Fill(1),
-        Constraint::Length(4),
+        Constraint::Length(6),
     ]);
 
     let [title_area, main_area, keybindings_area] = vertical_layout.areas(area);
@@ -65,24 +69,24 @@ pub fn skirmish_view(app: &App, area: Rect, buf: &mut Buffer) {
         let board_area: Rect = board_block.inner(main_area);
         board_block.render(main_area, buf);
 
-        let inner_board_area: Rect = board_area.inner(Margin {
+        let cells_area: Rect = board_area.inner(Margin {
             horizontal: 1,
             vertical: 1,
         });
 
-        let map_width: u16 = inner_board_area.width / (app.states.settings.map_width as u16);
-        let map_height: u16 = inner_board_area.height / (app.states.settings.map_height as u16);
-
-        Paragraph::new(format!(
-            "x = {}, y = {}, mw = {}, mh = {}",
-            inner_board_area.width, inner_board_area.height, map_width, map_height
-        ))
-        .block(Block::default())
-        .render(inner_board_area, buf);
+        BoardWidget::new(app, cells_area.width, cells_area.height).render(cells_area, buf);
     }
 
     {
-        let actions: Vec<Action> = vec![Action::Quit, Action::Quit2, Action::Esc];
+        let actions: Vec<Action> = vec![
+            Action::ScrollUp,
+            Action::ScrollDown,
+            Action::ScrollLeft,
+            Action::ScrollRight,
+            Action::Quit,
+            Action::Quit2,
+            Action::Esc,
+        ];
 
         KeybindingsWidget::new(actions).render(keybindings_area, buf);
     }