fix(rust-piscine): correct banner and drawing subjects (#3016)

* fixed a wrong data type given in the instructions but the expected function had it right

* Fixed the main function and added an instruction

---------

Co-authored-by: Pedro Ferreira <me.pedro.ferreira@gmail.com>

Author: madaghaxx

subjects/banner/README.md

@@ -22,7 +22,7 @@ println!("short hand: {}, long hand: {}, description: {}", d.short_hand, d.long_
 
 An associated **type** called `Callback` will also be provided. It should represent a function pointer which is going to be used in the structure and functions below. This function will represent the callback for the flag associated to it.
 
-A second structure named `FlagsHandler` will be given which just has one element: `flags: HashMap<(String, String), Callback>`. You'll also need to implement the following associated **functions**:
+A second structure named `FlagsHandler` will be given which just has one element: `flags: HashMap<String, Callback>`. You'll also need to implement the following associated **functions**:
 
 - `add_flag`, which adds the flag and callback function to the HashMap.
 - `exec_func`, which executes the function using the flag provided and returns the result. The callback should be executed with the first two arguments of the supplied `argv` argument. Return either the successful result from the callback or the error stringified.

subjects/drawing/README.md

@@ -30,11 +30,14 @@ In order to compile and run `main.rs`, you'll need to define some structures. Yo
 
 You'll also need to create the associated function `random` for `Line`, `Point` and `Circle`. You should derive their signatures from the usage.
 
+Each shape must be drawn in a different color.
+
 > Don't forget to add the dependencies in your Cargo.toml.
 
 ### Bonus
 
 You may optionally implement the following shapes, including the structures and traits needed to draw them:
+
 - `Pentagon`
 - `Cube`
 
@@ -54,13 +57,13 @@ fn main() {
 
     gs::Point::random(image.width, image.height).draw(&mut image);
 
-    let rectangle = gs::Rectangle::new(&gs::Point::new(150, 150), &gs::Point::new(50, 50));
+    let rectangle = gs::Rectangle::new(&gs::Point::new(150, 300), &gs::Point::new(50, 60));
     rectangle.draw(&mut image);
 
-    let triangle = gs::Triangle::new (
-            &gs::Point::new(500, 500),
-            &gs::Point::new(250, 700),
-            &gs::Point::new(700, 800),
+    let triangle = gs::Triangle::new(
+        &gs::Point::new(500, 500),
+        &gs::Point::new(250, 700),
+        &gs::Point::new(700, 800),
     );
     triangle.draw(&mut image);