5) Use the input function to ask for a dollar amount of a restaurant bill. Assume the entered dollar amount is a

# float (a number with a decimal part).

# Make sure there is a helpful message saying what should be entered.

# Print out a 20% tip (multiply the given number by 0.2) along with a helpful message. As an example, if the

# user entered 10.40 for the bill amount, the tip should be 2.08

# Do not worry about making the tip amount have 2 decimal places like a dollar amount would.