new package: cli for checking dependencies

[paperdave]

I've had issues with depcheck in the past. this is the tool I want to have:

• scan for all used imports like chalk or @paperdave/types, and how they are used.
• scan for dependencies specified in package.json scripts
• print dependencies specified in package.json but not actually used
• types imported count as a dev dependency unless the type in question is referenced in an exported type (i had an issue in Purplet where ForceSimplify was never resolved due to @paperdave/types being missing. this dependency lint tool should be able to catch that)
• a --write param to write the package.json file.