Docs: specify what is considered a vowel in this exercise

subjects/pig_latin/README.md

@@ -7,6 +7,7 @@ Create a **function** which transforms the string passed as an argument into Pig
 - If a word begins with a vowel, just add "ay" to the end.
 - If it begins with a consonant, then we take all consonants before the first vowel, move them to the end of the word, and then add "ay" at the end.
 - If a word starts with a consonant followed by "qu", move it to the end of the word, and then add an "ay" at the end.
+- Only the latin vowels will be considered as vowel(aeiou).
 
 ### Expected functions
 

subjects/piglatin/README.md

@@ -8,6 +8,7 @@ The rules used by Pig Latin are as follows:
 
 - If a word begins with a vowel, just add "ay" to the end.
 - If it begins with a consonant, then we take all consonants before the first vowel and we put them on the end of the word and add "ay" at the end.
+- Only the latin vowels will be considered as vowel(aeiou).
 
 If the word has no vowels, the program should print "No vowels".