Dav corrections

subjects/nrune/README.md

@@ -2,7 +2,7 @@
 
 ### Instructions
 
-Write a function that returns the nth `rune` of a `string`. If it's not possible it doesn't return anything.
+Write a function that returns the nth `rune` of a `string`. If not possible, it returns `0`.
 
 ### Expected function
 

subjects/printstr/README.md

@@ -30,7 +30,7 @@ And its output :
 
 ```console
 $ go run . | cat -e
-Hello World!$
+Hello World!
 $
 ```