Create a function that returns the sentence that contains the word at index n. Remember to include the full stop at the end.
txt = "I have a dog. I have a log. There is no stopping me now."
sentence_searcher(txt, 7) ➞ "I have a log."
# The word at index 7 is "log".
# The full sentence that contains the word at index 7 is "I have a log."
# Return the sentence.
sentence_searcher(txt, 2) ➞ "I have a dog."
sentence_searcher(txt, 4) ➞ "I have a log."
sentence_searcher(txt, -1) ➞ "There is no stopping me now."
# The index at -1 is the last word.
# The last word is "now".