docs(go quest 11): correct grammar of NodeI exercises

There are still some improvements to make - but we will make those after the current round of in progress selection piscines

subjects/listsort/README.md

@@ -4,8 +4,6 @@
 
 Write a function `ListSort` that sorts the nodes of a linked list by ascending order.
 
-- The `NodeI` structure will be the only one used.
-
 ### Expected function and structure
 
 ```go
@@ -19,6 +17,8 @@ func ListSort(l *NodeI) *NodeI {
 }
 ```
 
+> You will use **this** `NodeI` structure in subsequent exercises.
+
 ### Usage
 
 Here is a possible program to test your function :

subjects/sortedlistmerge/README.md

@@ -14,6 +14,8 @@ func SortedListMerge(n1 *NodeI, n2 *NodeI) *NodeI {
 }
 ```
 
+> You have already defined the `NodeI` structure in the `listsort` exercise.
+
 ### Usage
 
 Here is a possible program to test your function :

subjects/sortlistinsert/README.md

@@ -2,9 +2,11 @@
 
 ### Instructions
 
-Write a function `SortListInsert` that inserts `data_ref` in the linked list `l` while keeping the list sorted in ascending order.
+Create a function named `SortListInsert`, which accepts a pointer to the head of a _sorted_ linked list and an integer.
 
-- During the tests the list passed as an argument will be already sorted.
+The function should insert a new element into the list, with its `Data` set to the value of the integer. The element should be inserted so that the linked list remains sorted in ascending order by `Data`. The function should return the head of the list.
+
+Your function will only be tested with sorted linked lists.
 
 ### Expected function and structure
 
@@ -14,6 +16,8 @@ func SortListInsert(l *NodeI, data_ref int) *NodeI{
 }
 ```
 
+> You have already defined the `NodeI` structure in the `listsort` exercise.
+
 ### Usage
 
 Here is a possible program to test your function :