This function creates a new package.
Returns a new package if successful, otherwise NULL is returned.
-- Create a new zip package
local pak = CreatePackage("test.zip")
-- Create a stream
local stream = CreateBufferStream()
-- Write a line of text
stream:WriteLine("Hello!")
-- Insert the stream contents into the package
pak:AddFile("test.txt", stream.data)
-- Close the stream
stream:Close()
-- Close the package to finalize changes
pak:Close()
-- Open the zip file in the default program
RunFile("test.zip")