Add README.md

Signed-off-by: Ivan Bushchik <ivabus@ivabus.dev>

README.md

@@ -1,3 +1,40 @@
 # Matrix
 
-`todo!();`
+> Oh yes. Matrices.
+
+## Contents
+
+- `matrix` - core lib (just matrix addition and multiplication)
+- `matrix_graphics` - using rotation matrix to rotate things )
+
+## `matrix_graphics`
+
+### Run
+
+```bash
+cargo run
+```
+
+### Configure
+
+Edit these constants to configure code.
+
+```rust
+const WIDTH: u32 = 640;
+// width of window
+const HEIGHT: u32 = 480;
+// height of window
+const POLYGON: usize = 7;
+// count of sides of generated polygon (>= 2 for math reasons) 
+const CENTER_X: u32 = 320;
+// center of polygon by X
+const CENTER_Y: u32 = 240;
+// center of polygon by Y
+const RADIUS: u32 = 100;
+// radius of polygon
+const DEFAULT_ANGLE: f64 = 0.; //default rotation angle (in radians)
+```
+
+### License
+
+All code is available under the terms of the [MIT license](/LICENSE).