Fix post-install hook when publishing DS packages

[dev-rana-publicis]

Issue description

When trying to install/update the DS package on the platform with the command npm install --save @nciocpl/ncids-css@XXX @nciocpl/ncids-js@XXX, we get the following error from the log: error sh: 1: scripts/sync-uswds-packages.js: not found. Currently, it is running the post install hook from our package.json.

This was a bug introduced in #360

[bryanpizzillo]

@dev-rana-publicis I think you can take this ticket on. The problem is in packages/ncids-css/package.json. You need to change postinstall to prepare.

Well, I think that will fix it. So npm has a set of scripts that are called when you run npm commands. Most package managers honor this convention and mostly do the same.

With yarn we had a little bit of redirection -- basically we had a postinstall at the root, which called ncids:postinstall in ncids-css. Basically postinstall runs on everyones computers; however, since there is no @nciocpl/ncids package, the root file does not matter. With the move to npm things had to change because it worked differently -- I dunno if pnpm can handle the root postinstall, but we can try prepare first.

prepare only fires under certain conditions, most of which are local.

Basically you will need to test the following:

1. If you freshly clone and do a pnpm install can you still build storybook, run gatsby, or develop on the example site?
2. Does it build in CI/CD?
3. Can you publish?
4. Can you install it on the platform?

If you run into any issues, stop and shout. (i.e. maybe we need to rethink prepare if it does not work)