made a separate "create_hackpad" function that accepts title and contents

Hey, I saw that there was no existing function for making a new hackpad and at the same time setting its contents, so I pulled a `create_hackpad` function out of the old `create_new_hackpad`. 

There is now also a `create_blank_hackpad`, which does the same thing as the old `create_new_hackpad`, by invoking the lower level function with the appropriate parameters.