exercises/practice/anagram: add an append with instructions about the…

… order of the return values (#644)

exercises/practice/anagram/.docs/instructions.append.md

@@ -1,3 +1,7 @@
 # Instructions append
 
-As with Isogram, it's worth browsing what data types are already available in the system. Also remember to take the tests step by step and try to build up a solution bit by bit. The debugger can also be your friend, and remember that it's possible to evaluate any expression or variable to better visualise and and understand how it works.
+You must return the anagrams in the same order as they are listed in the candidate words.
+
+As with Isogram, it's worth browsing what data types are already available in the system.
+Also remember to take the tests step by step and try to build up a solution bit by bit.
+The debugger can also be your friend, and remember that it's possible to evaluate any expression or variable to better visualise and and understand how it works.