Revive builtIn scripts resolver

[texastoland]

You removed builtIn scripts in 17520b5. It'd be useful in my project to expose base scripts that dependent packages can override (I'll summarize better when it's not so late). It would only require changing 1) builtIn scripts to be resolved relative to node_modules and 2) add an option named something like preset.

[searls]

I'm open to this so long as it can be accomplished in a way that absolutely does not cause anyone's existing scripty use to accidentally invoke a shared script or for some bad actor to cleverly trigger a script by a scripty user. Arbitrary script execution of stuff in your node_modules (e.g. postinstall security fiascos) is appropriately scary enough as it is.

[texastoland]

I'll PR today. It's as safe as configuring path. The idea is to run default scripts from a specified "preset" package but still create your own locally. Kind of the way create-react-app works.