read-cmd-shim

Figure out what a cmd-shim
is pointing at. This acts as the equivalent of
fs.readlink.

$3

``
const readCmdShim = require('read-cmd-shim')

readCmdShim('/path/to/shim.cmd').then(destination => {
…
})

const destination = readCmdShim.sync('/path/to/shim.cmd')
`

$3

Reads the cmd-shim located at path and resolves with the _relative_
path that the shim points at. Consider this as roughly the equivalent of
fs.readlink.

This can read both .cmd style that are run by the Windows Command Prompt
and Powershell, and the kind without any extension that are used by Cygwin.

This can return errors that fs.readFile returns, except that they'll
include a stack trace from where readCmdShim was called. Plus it can
return a special ENOTASHIM exception, when it can't find a cmd-shim in the
file referenced by path`. This should only happen if you pass in a
non-command shim.

$3

Same as above but synchronous. Errors are thrown.