Rename prepack > prepack-cli so we don't run cli on yarn pack

[cblappert]

Release Notes: None

prepack command renamed to prepack-cli

[NTillmann]

Various places (including our GitHub landing page) mentions yarn prepack is the way to go. Do we really have to rename it? Why couldn't yarn prepack stay the main thing?

[cblappert]

Yarn and npm reserve "prepack" in package.json as a keyword that activates at certain times (specifically when you run yarn pack before it creates the tgz archive). Keeping the prepack command means that the cli will be run every time you run yarn pack.

Edit: this is also the case for npm pack (and depending on the version npm publish)

[hermanventer]

Please provide a description.

[hermanventer]

Please update the landing page and any internal references to "yarn prepack".

[facebook-github-bot]

@cblappert is landing this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[facebook-github-bot]

@cblappert is landing this pull request. If you are a Facebook employee, you can view this diff on Phabricator.