fix: match multi-word commands at parse time

[naveentehrpariya]

Fixes #170.

Problem

A command registered with a multi-word name is shown in --help but never matches while parsing, so matchedCommand is undefined and the action never fires:

const cli = cac('test')
cli.command('creds set <account>', 'set').action(() => {})
cli.command('creds get <account>', 'get').action((account) => {
  console.log('GET', account)
})

cli.parse(['node', 'test', 'creds', 'get', 'foo'])
// nothing runs; cli.matchedCommand === undefined

Cause

Matching compared the command name against only the first positional argument:

const commandName = parsed.args[0]            // 'creds'
if (command.isMatched(commandName)) { ... }   // 'creds get' === 'creds' -> false

The command's name (removeBrackets('creds get <account>')) is 'creds get', so it can never equal a single word.

Fix

Match the command name against as many leading positional arguments as the name has words, and slice off that many args for the command. Single-word commands are unaffected (wordCount === 1 reproduces the previous behaviour).

Tests

Added a multi-word command test asserting the command matches, the remaining args are correct, and the action receives the right value. It fails without this change and passes with it; the full suite (18 tests) is green.