basic save load

src/saveload.rs

@@ -0,0 +1,18 @@
+use serde::{Deserialize, Serialize};
+use crate::grid::Grid;
+use crate::tenori::Tenori;
+
+#[derive(Serialize, Deserialize)]
+pub struct PersistedTenori {
+    pub tempo: u32,
+    pub grids: Vec<Grid>
+}
+
+impl From<&Tenori> for PersistedTenori {
+    fn from(value: &Tenori) -> Self {
+        Self {
+            tempo: value.tempo,
+            grids: value.grids.iter().map(Grid::clone).collect()
+        }
+    }
+}