Summary:
Command which transpiles and bundles plugin code.
It is supposed to be used in "prepack" script for all open-sourced plugin packages to bundle them before publishing like this:
```
{
"devDependencies": {
"flipper-pkg": "latest"
},
"scripts": {
"prepack": "flipper-pkg bundle"
}
}
```
Also made directory parameter of other command "pack" optional so it also can be called from plugin directory simply by `flipper-pkg pack`.
Changelog: "flipper-pkg bundle" command for bundling plugins before publishing.
Reviewed By: mweststrate
Differential Revision: D21129691
fbshipit-source-id: 8f97bc950c28cf9ad8b0117c0e1d811ed1b988eb
Summary: Renamed command "bundle" to "pack" because the latter name better describe what the command does. Also I'm going to add another command which will only bundle the plugin code and it will be called "bundle" (see the next diff in this stack)
Reviewed By: mweststrate
Differential Revision: D21129690
fbshipit-source-id: 2dde30501c3776d6796c27c68d49948d1f84f822
