clarify instructions in the readme and rename bool to boolean

subjects/boolean.en.md

@@ -2,9 +2,10 @@
 
 ### Instructions
 
-Create a `.go` file and copy the code below into our file
+Create a `.go` file and copy the code below into that file
+and add the code necessary so the program works.
 
-- The main task is to return a working program.
+- The program must be submitted inside a folder with the name `boolean`.
 
 ```go
 func printStr(str string) {
@@ -36,11 +37,9 @@ func main() {
 ### Expected output
 
 ```console
+student@ubuntu:~/student/boolean$ go build
+student@ubuntu:~/student/boolean$ ./boolean "not" "odd"
 I have an even number of arguments
-```
+student@ubuntu:~/student/boolean$ ./boolean "not even"
-
-### Or
-
-```console
 I have an odd number of arguments
 ```