Rust piscine: Add audits and bonus questions for the exercise drawing

subjects/drawing/README.md

@@ -28,6 +28,12 @@ second the maximum y value that a point can have
 
 Don't forget to add the dependencies in your Cargo.toml.
 
+#### Bonus
+
+- Implement drawing a pentagon
+
+- Implement drawing a cube
+
 ### Notions
 
 - [Image processing library](https://docs.rs/raster/0.2.0/raster/)

subjects/drawing/audit/README.md

@@ -0,0 +1,18 @@
+#### Functional
+
+##### Run the command `cargo run`
+
+###### Does the program compile and run without any error or warning?
+
+###### Does the program produces a png file called image.png?
+
+###### Does the image contain lines, circles, rectangles and triangles?
+
+###### Are the shapes drawn with different colors?
+
+#### Bonus
+
+###### +Can you draw a pentagon?
+
+###### +Can you draw a cube?
+