Allow for a leading newline for files with header comments

[gaymeowing]

Currently if I make a file with a header comment stylua will trim the leading newline before the header comment, making the header comment not look as nice:

Before:

-- create signal
-- generic signal module

local signal = {}

return signal

After:

-- create signal
-- generic signal module

local signal = {}

return signal

It'd be nice if stylua could detect header comments that start with the file name, with it being case-insensitive and allowing spaces in place of - or _ in the file name.