* trust option to indicate whether input text is trusted
* Revamp into trust contexts beyond just command
* Document new trust function style
* Fix screenshot testing
* Use trust setting in \url and \href
* Check `isTrusted` in `\url` and `\href` (so now disabled by default)
* Automatically compute `protocol` from `url` in `isTrusted`, so it
doesn't need to be passed into every context.
* Document untrusted features in support list/table
* Existing tests trust by default
* remove allowedProtocols and fix flow errors
* remove 'allowedProtocols' from documentation
* add a comment about a flow error, rename urlToProtocol to protocolFromUrl
* add tests test that use function version of trust option
* default trust to false in MathML tests
* fix test title, remove 'trust: false' from test settings since it's the default
* Change `npm run` to `yarn`
* Export `commander` program if required as module
* Move `prestart` (cli.md generation) to build.js
* Normalize script names
* Change `yarn prestart` to `node lib/build.js`
* Use local built CSS and fonts
* Move stylesheet after the first paragraph
* Remove prestart script
