Add exercise insertion_sort

subjects/insertion_sort/README.md

@@ -0,0 +1,58 @@
+## insertion_sort
+
+### Instructions
+
+The insertion sort algorithm:
+
+- To sort an array of size n in ascending order:
+
+1. Iterate from slice[1] to slice[n] over the slice.
+
+2. Compare the current element (key) to its predecessor.
+
+3. If the key element is smaller than its predecessor, compare it to the elements before. Move the greater elements one position up to make space for the swapped element.
+
+Here is a visual example of sorting a slice step by step using the insertion sort algorithm.
+
+![](Insertion-Sort-demo.jpg)
+**Figure 1** - Step by step execution of the algorithm insertion sort
+
+- Implement the algorithm insertion sort by creating a function `insertion_sort(slice, steps)` that executes the iterations of the algorithm the number of steps indicated by the parameter `steps`. See the [Usage](#usage) for more information.
+
+### Notion
+
+### Expected Function
+
+```rust
+pub fn insertion_sort(slice: &mut [i32], steps: usize) {
+}
+```
+
+### Usage
+
+Here is a possible program to test your function
+
+```rust
+fn main() {
+	let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
+	// executes the first iteration of the algorithm
+	insertion_sort(&mut target, 1);
+	println!("{:?}", target);
+
+	let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
+	let len = target.len();
+	// executes len - 1 iterations of the algorithm
+	// i.e. sorts the slice
+	insertion_sort(&mut target, len - 1);
+	println!("{:?}", target);
+}
+```
+
+And it's output:
+
+```console
+student@ubuntu:~/[[ROOT]]/test$ cargo run
+[3, 5, 7, 2, 1, 6, 8, 4]
+[1, 2, 3, 4, 5, 6, 7, 8]
+student@ubuntu:~/[[ROOT]]/test$
+```

subjects/matrix_transposition_4by3/README.md

@@ -1,4 +1,4 @@
-## matrix_transposition
+## matrix_transposition_4by3
 
 ### Instructions
 
@@ -13,8 +13,10 @@
 Example:
 
 ```
-( a b )   __ transposition __>   ( a d )
+( a b c )   __ transposition __>   ( a d g j )
-( c d )                          ( b d )
+( d e f )                          ( b e h k )
+( g h i )                          ( c f i l )
+( j k l )
 ```
 
 - Matrix must implement Debug, PartialEq and Eq. You can use derive
@@ -25,7 +27,7 @@ Example:
 
 [Chapter 7]( https://doc.rust-lang.org/stable/book/ch07-03-paths-for-referring-to-an-item-in-the-module-tree.html )
 
-### Expected Function
+### Expected Function and Structs
 
 ```rust
 pub struct Matrix4by3(