Finalize the v0.7 release

[iamh2o]

Objective

• Finalize and announce the v0.7 release of daylily.

Tasks

• [ ] Scrub all extraneous smk files from the repository.
• [ ] Take a pass at cleaning up the to-be-released smk, script and other tools.
• [ ] Update the README.md to reflect the new release.
• [ ] Update the CHANGELOG.md to reflect the new release.
• [ ] Update the LICENSE to reflect the new release.
• [ ] scrub all dev documentation, and slim down dramatically.
• [ ] Record install video.