Version 7.0.0

Major

• Updated Node.js support to ^12.20.0 || ^14.13.1 || >= 16.0.0.
• Updated dev dependencies, some of which require newer Node.js versions than previously supported.

Patch

• Updated dependencies.
• Replaced the package prepare script with a jsdoc script.
• Added a package test:jsdoc script that checks the readme API docs are up to date with the source JSDoc.
• Also run GitHub Actions CI with Node.js v17, and drop v15.
• Prevent outputting the Node.js internal async Promise.all (index 0) error stack frame generated by recent Node.js versions that stack-utils fails to clean, (see tapjs/stack-utils#63).
• Readme tweaks.