Replace the numbers in a string with their binary form.
replace_nums("I have 2 sheep.") ➞ "I have 10 sheep."
replace_nums("My father was born in 1974.10.25.") ➞ "My father was born in 11110110110.1010.11001."
replace_nums("10hell76o4 boi") ➞ "1010hell1001100o100 boi"