rename plf HINTS and regenerate READMEs

exercises/protein-translation/README.md

 
 RNA: `"AUGUUUUCUUAAAUG"` =>
 
-Codons: `"AUG", "UUU", "UCU", "UAG", "AUG"` =>
+Codons: `"AUG", "UUU", "UCU", "UAA", "AUG"` =>
 
 Protein: `"Methionine", "Phenylalanine", "Serine"`
 
-Note the stop codon terminates the translation and the final methionine is not translated into the protein sequence.
+Note the stop codon `"UAA"` terminates the translation and the final methionine is not translated into the protein sequence.
 
 Below are the codons and resulting Amino Acids needed for the exercise.