added todo

README.md

@@ -35,6 +35,14 @@ placing clue numbers, so every puzzle has a solution by construction.
 | 25×25 | 🔜     |
 
 ---
+## TODO
+- [ ] Fix window size to auto resize when changing game mode
+- [ ] Show number of cells selected during a mouse drag, before placing
+- [ ] Remove ability to select just 1 cell
+- [ ] Add some kind of zoom feature
+   - Scroll wheel
+   - and/or a ui button for zoom in/out
+---
 
 ## Using the package locally (before it lands in nixpkgs)