changed readme

README.md

@@ -2,6 +2,14 @@
 A calculator application written in C# and Fusion.
 Using Avalonia to draw GUI.
 
+You can just type expression if tou don't like pressing GUI buttons.
+
+**Key binds:**
+- `Enter`: `=`
+- `Del`: `AC`
+
+![screenshot](./screenshot.jpg)
+
 ## Building
 Requirements: git, bash, [dotnet8](https://dotnet.microsoft.com/en-us/download/dotnet/8.0), [fut](https://github.com/fusionlanguage/fut)