API documentation missing information on available global and command options.

Such as `--cwd` and `--config`

Again, this is specifically for the API:
```
var Hexo = require('hexo');
var hexo = new Hexo(process.cwd(), {});
hexo.init().then(function(){
hexo.call('generate', {}).then(function(){
// ...
});
});
```

and etc. The options used for the command line version exist for the javascript API version or am I confused at the usage of the API?