Bundle command

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

desktop/pkg/README.md

@@ -24,8 +24,26 @@ USAGE
 <!-- usagestop -->
 # Commands
 <!-- commands -->
+* [`flipper-pkg bundle [DIRECTORY]`](#flipper-pkg-bundle-directory)
 * [`flipper-pkg help [COMMAND]`](#flipper-pkg-help-command)
-* [`flipper-pkg pack DIRECTORY`](#flipper-pkg-pack-directory)
+* [`flipper-pkg pack [DIRECTORY]`](#flipper-pkg-pack-directory)
+
+## `flipper-pkg bundle [DIRECTORY]`
+
+transpiles and bundles plugin
+
+```
+USAGE
+  $ flipper-pkg bundle [DIRECTORY]
+
+ARGUMENTS
+  DIRECTORY  [default: .] Path to plugin package directory for bundling. Defaults to the current working directory.
+
+EXAMPLE
+  $ flipper-pkg bundle optional/path/to/directory
+```
+
+_See code: [src/commands/bundle.ts](https://github.com/facebook/flipper/blob/v0.37.0/src/commands/bundle.ts)_
 
 ## `flipper-pkg help [COMMAND]`
 
@@ -44,16 +62,20 @@ OPTIONS
 
 _See code: [@oclif/plugin-help](https://github.com/oclif/plugin-help/blob/v2.2.3/src/commands/help.ts)_
 
-## `flipper-pkg pack DIRECTORY`
+## `flipper-pkg pack [DIRECTORY]`
 
 packs a plugin folder into a distributable archive
 
 ```
 USAGE
-  $ flipper-pkg pack DIRECTORY
+  $ flipper-pkg pack [DIRECTORY]
+
+ARGUMENTS
+  DIRECTORY  [default: .] Path to plugin package directory to pack. Defaults to the current working directory.
 
 OPTIONS
-  -o, --output=output  [default: .] Where to output the package, file or directory. Defaults to '.'.
+  -o, --output=output  [default: .] Where to output the package, file or directory. Defaults to the current working
+                       directory.
 
 EXAMPLE
   $ flipper-pkg pack path/to/plugin