Split off header file and improve readme

[Granjow]

This PR updates the Readme to help the user decide when to use this library and when to use NeoPixel, and splits the lbirary from the demo code.

[bigjosh]

Hmm... The readme changes are very helpful. Thanks!

I'm not sure how I feel about breaking out the header file. I think many Arduino people are not C people and do not really understand headers. I like having everything contained in the single INO so when you open it, everything is right there in front of you.

If I was going to break things out into a proper library, then I'd use C++ templates to make it so that you could, say, override the timing #defines with a parameter to the template function and even an abstraction for assigning the pins on different board types.

Maybe making a nice library is a new repo, with this one remaining just the simplest example code? Would you be interested in doing that?

Thoughts?

Thanks again!

[Granjow]

That sounds good, yes! Are you going to create the new repository? I think I can find out how to use C++ templates, some years have passed since I have used C++ regularly, so it is time for a refresher anyway.

Do you have experience with publishing it to the official Arduino library?

[bigjosh]

Do you have experience with publishing it to the official Arduino library?
I do not, but I do not think that is critical. It is easy for anyone to install any library these days with just a ZIP file, and it is easy to find libraries with google! :)

[Granjow]

Ok. Will start working on it and also include the timings other users listed in #10!

[bigjosh]

Replaced by #16