Readme should be more accurate

[zhanzhenzhen]

1. It seems that options are not limited to the listed 5. "basedir", "extensions" in the resolve package can also be used, but I can't find that in readme.
2. There are some typo in the examples. For example,

var shims = {
    http: '/your/path/to/http.js'
};

var resolve = require('browser-resolve');
resolve('fs', { modules: shims }, function(err, path) {
    console.log(path);
});

I think it should be resolve('http')?

In the "Browser Field" section, why is there a "chromeapp" property?

[marionebl]

@zhanzhenzhen is this fixed with the latest changes to readme.md?