Move scripts to Github

I've created a Github repo to host the scripts and track their changes over time. Some of the scripts are already there, others are being added as I have time.

⇒ https://github.com/kg4zow/rm2-scripts

TODO

Create dirctories in the Github repo for each already-existing script on this site.

• convert each scripts page on this site, to a README.md file in each script's directory

• for template scripts, write/test individual generate scripts to make sure samples and thumbnails look right in the Github web interface

• update pages in this book to point to Github for each script, so I don't have to keep maintaining two sets of documentation.